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Client libraries

The Vertica client driver libraries provide interfaces for connecting your client applications (or third-party applications such as Cognos and MicroStrategy) to your Vertica database.

The Vertica client driver libraries provide interfaces for connecting your client applications (or third-party applications such as Cognos and MicroStrategy) to your Vertica database. The drivers simplify exchanging data for loading, report generation, and other common database tasks.

There are three separate client drivers:

  • Open Database Connectivity (ODBC)—the most commonly-used interface for third-party applications and clients written in C, Python, PHP, Perl, and most other languages.

  • Java Database Connectivity (JDBC)—used by clients written in the Java programming language.

  • ActiveX Data Objects for .NET (ADO.NET)—used by clients developed using Microsoft's .NET Framework and written in C#, Visual Basic .NET, and other .NET languages.

Client driver standards

The Vertica client drivers are compatible with the following driver standards:

  • The ODBC driver complies with version 3.5.1 of the ODBC standard.

  • The version of JDBC used depends on the version of your JVM. For details, see JDBC feature support.

  • ADO.NET drivers conform to .NET framework 3.0 specifications.

The drivers do not support some of the optional features in the standards. See ODBC feature support and JDBC feature support and Using ADO.NET for details.

1 - Client driver and server version compatibility

Backward compatibility between Vertica server and client drivers works in both directions; Vertica server is compatible with all previous versions of client drivers, and all new client drivers are compatible with most versions of Vertica server.

Backward compatibility between Vertica server and client drivers works in both directions.

The Vertica server is compatible with all previous versions of client drivers, and all new client drivers are compatible with most versions of Vertica server. This compatibility lets you upgrade your Vertica server without having to immediately upgrade your client software, and use new client software with older versions of Vertica. Occasionally, however, individual features of a new server version might be unavailable through older drivers.

Client Compatible Server Versions
ODBC 9.2.x and above
JDBC 9.2.x and above
ADO.NET 9.2.x and above
FIPS-enabled ODBC FIPS-enabled 9.2.x and above (FIPS cannot be enabled in Vertica 9.3.x and 10.0.x.).
FIPS-enabled JDBC FIPS-enabled 9.2.x and above (FIPS cannot be enabled in Vertica 9.3.x and 10.0.x.)

2 - Client drivers

You must install the Vertica client drivers to access Vertica from your client application.

You must install the Vertica client drivers to access Vertica from your client application. The drivers create and maintain connections to the database and provide APIs that your applications use to access your data. The client drivers support connections using JDBC, ODBC, and ADO.NET.

Client driver standards

The client drivers support the following standards:

  • ODBC drivers conform to ODBC 3.5.1 specifications.

  • JDBC drivers conform to JDK 5 specifications.

  • ADO.NET drivers conform to .NET framework 3.0 specifications.

2.1 - Installing and configuring client drivers

You can access your Vertica database with various programming languages and tools by installing the appropriate client driver.

You can access your Vertica database with various programming languages and tools by installing the appropriate client driver. The following table lists the required client drivers for each access method:

Client Driver Language/Tool
JDBC Java
ODBC
vertica-python Python (native client)
ADO.NET C#
vertica-nodejs JavaScript
vertica-sql-go Go

2.1.1 - Windows client driver installer

All available client drivers for Windows are included in the Vertica Client Drivers and Tools installer.

All available client drivers for Windows are included in the Vertica Client Drivers and Tools installer. This installs the following components on systems that meet the prerequisites. The individual components may require additional configuration before use, so navigate to their pages linked below for more information:

2.1.1.1 - System prerequisites

The Vertica Client Drivers and Tools for Windows has basic system prerequisite requirements.

The Vertica Client Drivers and Tools for Windows has basic system prerequisite requirements. The pack also requires that specific Microsoft components be installed for full integration.

For a list of all prerequisites, see Client drivers support in the Supported Platforms document.

Fully update your system

Before you install the Vertica driver package, verify that your system is fully up to date with all Windows updates and patches. See the documentation for your version of Windows for instructions on how to run Windows update. The Vertica client libraries and vsql executable install updated Windows libraries that depend on Windows service packs. Be sure to resolve any issues that block the installation of Windows updates.

If your system is not fully up-to-date, you may receive error messages about missing libraries such as api-ms-win-crt-runtime-l1-1-0.dll when starting vsql.

2.1.1.1.1 - .NET framework

The Vertica Client Drivers and Tools for Windows requires and prompts you to install the Microsoft .NET Framework 4.6 if it is not installed.

The Vertica Client Drivers and Tools for Windows requires and prompts you to install the Microsoft .NET Framework 4.6 if it is not installed.

To manually install the Microsoft .NET Framework 4.6, see the Microsoft documentation.

2.1.1.1.2 - Microsoft SQL server

Use SQL Server 2012, 2014 or 2016.

Use SQL Server 2012, 2014 or 2016. The Vertica Client Drivers and Tools for Windows installer enables support for the following:

  • SQL Server 2012, 2014, and 2016:

    • SQL Server Integration Services (SSIS)

    • SQL Server Reporting Services (SSRS)

    • SQL Server Analysis Services (SSAS)

  • SQL Server using 2012, 2013, and 2015—SQL Server Data Tool - Business Intelligence (SSDT-BI)

To use the enhanced Vertica .NET support, you must first install SQL Server. Then, you can install the Client Drivers and Tools for Windows. The following components must be installed on the SQL server:

For... Install...
SSAS The Analysis Services Instance Feature.
SSRS The Reporting Services Instance Feature.
SSIS (Data Type Mappings) The SQL Server Integration Services Shared Feature.
SSDT-BI (Visual Studio 2012, 2013, or 2015) SQL Server Data Tool - Business Intelligence Shared Feature only after installing Microsoft Visual Studio 2012, 2013, or 2015.

2.1.1.2 - Uninstalling, modifying, or repairing the client drivers and tools

To uninstall, modify, or repair the client drivers and tools, run the Client Drivers and Tools for Windows installer.

To uninstall, modify, or repair the client drivers and tools, run the Client Drivers and Tools for Windows installer.

The installer provides three options:

Action Description
Modify Remove installed client drivers and tools or install missing client drivers and tools.
Repair Reinstall already-installed client drivers and tools.
Uninstall Uninstall all of the client drivers and tools.

Silently uninstall the client drivers and tools

  1. As a Windows Administrator, open a command-line session, and change directory to the folder that contains the installer.

  2. Run the command:

    VerticaSetup.exe -q -uninstall
    

The client drivers and tools are silently uninstalled.

2.1.2 - FIPS client drivers

Vertica offers a FIPS-compliant version of the ODBC and JDBC client drivers.

Vertica offers a FIPS-compliant version of the ODBC and JDBC client drivers.

2.1.2.1 - Installing the FIPS client driver for JDBC

Vertica offers a JDBC client driver that is compliant with the Federal Information Processing Standard (FIPS).

Vertica offers a JDBC client driver that is compliant with the Federal Information Processing Standard (FIPS). Use this JDBC client driver to access systems that are FIPS-compatible. For more information on FIPS, see Federal information processing standard.

Implementing FIPS on a JDBC client requires a third-party JRE extension called BouncyCastle, a collection of APIs used for cryptography. Use BouncyCastle APIs with JDK 1.7 and 1.8, and a supported FIPS-compliant operating system.

The following procedure adds the FIPS BouncyCastle .jar as a JVM JSSE provider:

  1. Download the BouncyCastle FIPS .jar file bc-fips-1.0.0.jar.

  2. Add bc-fips-1.0.0.jar as a JRE library extension:

    path/to/jre/lib/ext/bc-fips-1.0.0.jar
    
  3. Add BouncyCastle as an SSL security provider in <path to jre>/lib/security/java.security:

    security.provider.1=org.bouncycastle.jcajce.provider.BouncyCastle FipsProvider
    security.provider.2=com.sun.net.ssl.internal.ssl.Provider BCFIPS
    security.provider.3=sun.security.provider.Sun
    
  4. Use the following JVM java -D system property command arguments to set the KeyStore and TrustStore files to BCFIPS:

    export JAVA_OPTS="$JAVA_OPTS -Djavax.net.ssl.keyStoreProvider=BCFIPS
    export JAVA_OPTS="$JAVA_OPTS -Djavax.net.ssl.trustStoreProvider=BCFIPS
    
  5. Set the default type for the KeyStore implementation to BCFKS in path/to/jre/lib/security/java.security:

    keystore type=BCFKS
    ssl.keystore.type=BCFKS
    
  6. Create the BCFKS-type keystore and truststore:

    cd path/to/jre
    -storetype BCFKS
    -providername BCFIPS
    -providerclass org.bouncycastle.jcajce.provider.BouncyCastleFipsProvider
    -provider org.bouncycastle.jcajce.provider.BouncyCastleFipsProvider
    -providerpath bc-fips-1.0.0.jar
    -alias CARoot
    -import -file path/to/server.crt.der
    
  7. When prompted, enter the keystore password. The following message is displayed to confirm that a certificate was added to the keystore:

    "Certificate was added to the keystore"
    
  8. Run the Java program with SSL DB:

    1. Copy the vertica.kafka.keystore.bcfks keyStore from path/to/jre/lib/ext/ to the Java program folder.

    2. Convert the Vertica server certificate to a form that Java understands:

      $ path/to/java/bin/keytool -keystore verticastore -keypasswd -storepass password
                              -importkeystore -noprompt -alias verticasql -import -file server.crt.der
      
    3. Install JDBC.

  9. Test the implementation:

    $ java -Djavax.net.debug=ssl -Djavax.net.ssl.keyStore='vertica.kafka.keystore.bcfks'
    -Djavax.net.ssl.keyStorePassword='password'
    -Djavax.net.ssl.trustStore='path/to/verticastore'
    -Djavax.net.ssl.trustStorePassword='password'
    -cp .:vertica-jdbc-12.0.0-0.jar FIPSTest
    

2.1.2.2 - Installing the FIPS client driver for ODBC and vsql

Vertica offers a FIPS client for FIPS-compatible systems.

Vertica offers a FIPS client for FIPS-compatible systems. A FIPS-compatible system is FIPS-enabled and includes the OpenSSL libraries.

The FIPS client supports ODBC and vsql and is offered in 64-bit only.

Prerequisites

Verify that your host system is running a FIPS-compliant operating system that Vertica supports.

The FIPS client installer checks your host system for the value of the sysctl parameter, crypto.fips_enabled. You must set this parameter to 1 (enabled). If your host is not enabled, the client does not install.

Installing the FIPS client

To install the FIPS client driver package:

  1. Download the FIPS client package from the Vertica driver downloads page.

  2. Log in to the client system as root.

  3. Install the RPM package that you downloaded:

    # rpm -Uvh package_name.rpm
    

For ODBC, after you have installed the client package, create a DSN and set some additional configuration parameters. For more information, see:

You can optionally add the vsql client to your PATH environment variable so that you do not need to enter its full path to run it. To do so, add the following to the .profile file in your home directory or the global /etc/profile file:

export PATH=$PATH:/opt/vertica/bin

How the client searches for OpenSSL libraries

When you launch the client application to connect to the server, the client searches for and loads the OpenSSL libraries libcrypto.so.10 and libssl.so.10 for supported OpenSSL versions:

  • The client first checks to see if LD_LIBRARY_PATH is set.

  • If the LD_LIBARY_PATH location does not include the libraries, it checks RunPath, either /opt/vertica/lib or within the ODBC or vsql directory structure (../lib).

The following figure depicts the search process for the OpenSSL libraries:

2.1.3 - JDBC client driver

The Vertica JDBC client driver conforms to JDK 5 specifications and provides an interface for communicating with the Vertica database with Java.

The Vertica JDBC client driver conforms to JDK 5 specifications and provides an interface for communicating with the Vertica database with Java. For details on this and other APIs, see API Reference.

To install the JDBC client driver, see Installing the JDBC client driver.

2.1.3.1 - Installing the JDBC client driver

The JDBC client driver conforms to JDK 5 specifications.

The JDBC client driver conforms to JDK 5 specifications. Download the JDBC client driver according to your environment and requirements. If you need a FIPS-compliant driver, see Installing the FIPS client driver for JDBC.

Installing Vertica from the RPM automatically installs the JDBC client driver. To use the JDBC client driver, you just need to add the Vertica JDBC .jar to your CLASSPATH.

To manually install the JDBC client driver:

  1. Download the version of the JDBC client driver from the Client Drivers downloads page compatible with your version of Vertica.

  2. Copy the .jar file to a directory in your Java CLASSPATH on every client system with which you want to access Vertica. You can either:

    • Copy the .jar file to its own directory (such as /opt/vertica/java/lib) and then add that directory to your CLASSPATH (recommended). See Modifying the Java CLASSPATH for details.

    • Copy the .jar file to directory that is already in your CLASSPATH (for example, a directory where you have placed other .jar files on which your application depends).

    • Copy the .jar file to the system-wide Java Extensions directory. The exact location differs between operating systems. Some examples include:

      • Windows: C:\Program Files\Java\jrex.x.x_x\lib\ext\

      • Mac OS: /Library/Java/Extensions or /Users/username/Library/Java/Extensions

  3. Create a connection to test your configuration.

2.1.3.2 - Modifying the Java CLASSPATH

The CLASSPATH environment variable contains a list of directories where the Java runtime looks for library class files.

The CLASSPATH environment variable contains a list of directories where the Java runtime looks for library class files. For your Java client code to access Vertica, you must add to the CLASSPATH the directory containing the Vertica JDBC .jar.

You can optionally add to the CLASSPATH a symbolic link vertica-jdbc-x.x.x.jar (where x.x.x is a version number) that points to the JDBC library .jar file, rather than the .jar file itself.

Using the symbolic link ensures that any updates to the JDBC library .jar file (which will use a different filename) will not invalidate your CLASSPATH setting, since the symbolic link's filename will remain the same. You just need to update the symbolic link to point at the new .jar file.

Linux and OS X

The following examples use a POSIX-compliant shell.

To set the CLASSPATH for the current session:

$ export CLASSPATH=$CLASSPATH:/opt/vertica/java/lib/vertica-jdbc-x.x.x.jar

To set the CLASSPATH for every session, add the following to your start-up file (such as ~/.profile or /etc/profile:

$ export CLASSPATH=$CLASSPATH:/opt/vertica/java/lib/vertica-jdbc-x.x.x.jar

Windows

Provide the class paths to the .jar, .zip, or .class files.

C:> SET CLASSPATH=classpath1;classpath2...

For example:

C:> SET CLASSPATH=C:\java\MyClasses\vertica-jdbc-x.x.x.jar

As with the Linux/UNIX settings, this setting only lasts for the current session. To set the CLASSPATH permanently, set an environment variable:

  1. On the Windows Control Panel, click System.

  2. Click Advanced or Advanced Systems Settings.

  3. Click Environment Variables.

  4. Under User variables, click New.

  5. In the Variable name box, type CLASSPATH.

  6. In the Variable value box, type the path to the Vertica JDBC .jar file on your system (for example, C:\Program Files (x86)\Vertica\JDBC\vertica-jdbc-x.x.x.jar)

Specifying the library directory in the Java command

Another, OS-agnostic way to tell the Java runtime where to find the Vertica JDBC driver is to explicitly add the directory containing the .jar file to the Java command line using either the -cp or -classpath argument. For example, you can start your client application with:

java -classpath /opt/vertica/java/lib/vertica-jdbc-x.x.x.jar myapplication.class

Your Java IDE may also let you add directories to your CLASSPATH, or let you import the Vertica JDBC driver into your project. See your IDE documentation for details.

2.1.4 - ODBC client driver

The Vertica ODBC client driver provides an interface for creating client applications with several languages:.

The Vertica ODBC client driver provides an interface for creating client applications with several languages:

To install ODBC, see Installing the ODBC client driver.

2.1.4.1 - Installing the ODBC client driver

To install ODBC, follow the instructions according to your platform.

To install ODBC, follow the instructions according to your platform. For a list of supported platforms, see Client drivers support.

This page covers a non-FIPS installation. To install ODBC on a FIPS-compliant system, see Installing the FIPS client driver for ODBC and vsql.

Installing on Linux

Installing Vertica from the RPM automatically installs the ODBC client driver, so you do not need to install them again on the machine running Vertica. To use the ODBC client driver in this case, create a DSN.

To install the ODBC client driver manually on other machines:

  1. Log in to the client system as root.

  2. Verify that your system has a supported ODBC driver manager.

  3. Download the ODBC client driver for Linux in the format appropriate for your distribution.

  4. Install or extract the driver:

    • If you downloaded the .rpm, install the driver:

      $ rpm -Uvh driver_name.rpm
      
    • If you downloaded the .tar, create the /opt/vertica/ directory if it does not already exist, copy the .tar to it, navigate to it, and extract the .tar:

      
      $ mkdir -p /opt/vertica/
      $ cp driver_name.tar.gz /opt/vertica/
      $ tar vzxf driver_name.tar.gz
      

      This creates two directories:

      • /opt/vertica/include: Contains the header file.

      • /opt/vertica/lib64/ (64-bit) or /opt/vertica/lib/ (32-bit): Contains library files.

  5. Set the following ODBC driver settings in vertica.ini. For details on each, see ODBC driver settings:

    • ErrorMessagesPath: Required, the path of the directory containing the ODBC driver's error message files.

    • ODBCInstLib: The path to the ODBC installer library. This is only required if the driver manager's installation library is not in the environment variables LD_LIBRARY_PATH or LIB_PATH.

    • DriverManagerEncoding: The UTF encoding standard used by the driver manager. This is only required if your driver manager does not use UTF-8.

    The following is an example configuration in vertica.ini:

    • Use encoding for the 64-bit UNIXODBC driver manager.

    • Use the error messages defined in the standard Vertica 64-bit ODBC driver installation directory.

    • Log all warnings and more severe messages to log files in /tmp/

      [Driver]
      DriverManagerEncoding=UTF-16
      ODBCInstLib=/usr/lib64/libodbcinst.so
      ErrorMessagesPath=/opt/vertica
      LogLevel=4
      LogPath=/tmp
      
  6. Create a DSN.

Installing on macOS

To install the ODBC client driver on macOS:

  1. Verify that your system has a compatible driver manager. The driver is designed to be used with the standard iODBC Driver Manager that ships with macOS. You can also use unixODBC.

  2. Download the ODBC client driver.

  3. If you installed a previous version of the ODBC driver, your system might already have a registered driver named "Vertica". You must remove or rename this older version of the driver before installing a new version from the .pkg installer. Renaming the older version allows you to retain the old version after you install the new one.

  4. Run the installer.

  5. Create a DSN.

Installing silently

  1. Log into the client macOS in one of two ways:

    • As an administrator account if you are installing the driver for system-wide use.

    • As the user who needs to use the Vertica ODBC driver.

  2. Open a terminal.

  3. Install the .pkg file containing the ODBC driver using the command:

    sudo installer -pkg path/to/client/driver/vertica-odbc-xx.x.x-x.pkg -target /
    

Installing on Windows

To install the ODBC client driver on Windows:

  1. Download the client driver installer for Windows.

  2. Run the installer.

  3. Create a DSN.

Installing silently

  1. Open a terminal as an Administrator.

  2. Run the following command to silently install the drivers to C:\Program Files\Vertica Systems:

    VerticaSetup.exe -q -install InstallFolder="C:\Program Files\Vertica Systems"
    

2.1.4.2 - Upgrading and downgrading ODBC

To upgrade ODBC:.

Linux

To upgrade ODBC:

  1. Uninstall the current version of the driver.

  2. Install the new version of the driver.

macOS

To upgrade or downgrade ODBC:

  • Upgrade: Newly installed versions of the Vertica ODBC driver for macOS automatically upgrade the relevant driver system settings. Any DSNs associated with a previous version of the driver are not affected, except that they begin using the newer version of the driver.

  • Downgrade: Run the uninstall script to remove the current version of the Vertica ODBC driver for macOS. Complete this step before installing an older driver version.

Windows

  1. Download the Windows client driver installer.

  2. Run the installer and follow the prompts to upgrade the driver. The installer upgrades existing drivers in place.

  3. Reboot your system.

2.1.4.3 - Uninstalling ODBC

If you installed ODBC with the .rpm:.

Linux

If you installed ODBC with the .rpm:

$ rpm -e package_name

If you installed ODBC with the .tar, delete the directory manually.

macOS

Uninstalling the macOS ODBC Client-Driver does not remove any existing DSNs associated with the driver.

To uninstall:

  1. Open a terminal window.

  2. Run the command:

    sudo /Library/Vertica/ODBC/bin/Uninstall
    

Windows

  1. Open the Add or Remove Programs menu.

  2. EIther uninstall the Vertica Client Installer to remove all client drivers from the system or, to only uninstall ODBC, uninstall the following applications:

    • Vertica ODBC Driver (32 Bit)

    • Vertica ODBC Driver (64 Bit)

2.1.4.4 - Creating an ODBC data source name (DSN)

A Data Source Name (DSN) is the logical name that is used by Open Database Connectivity (ODBC) to refer to the driver and other information that is required to access data from a data source.

A Data Source Name (DSN) is the logical name that is used by Open Database Connectivity (ODBC) to refer to the driver and other information that is required to access data from a data source. Whether you are developing your own ODBC client code or you are using a third-party tool that needs to access Vertica using ODBC, you need to configure and test a DSN. The method you use depends upon the client operating system you are using.

Refer to the following sections for information specific to your client operating system.

2.1.4.4.1 - Creating an ODBC DSN for Linux

You define DSN on Linux and other UNIX-like platforms in a text file.

You define DSN on Linux and other UNIX-like platforms in a text file. Your client's driver manager reads this file to determine how to connect to your Vertica database. The driver manager usually looks for the DSN definitions in two places:

  • /etc/odbc.ini

  • ~/.odbc.ini (a file named .odbc.ini in the user's home directory)

Users must be able to read the odbc.ini file in order to use it to connect to the database. If you use a global odbc.ini file, consider creating a UNIX group with read access to the file. Then, add the users who need to use the DSN to this group.

The structure of these files is the same—only their location differs. If both files are present, the ~/.odbc.ini file usually overrides the system-wide /etc/odbc.ini file.

odbc.ini file structure

The odbc.ini is a text file that contains two types of lines:

  • Section definitions, which are text strings enclosed in square brackets.

  • Parameter definitions, which contain a parameter name, an equals sign (=), and then the parameter's value.

The first section of the file is always named [ODBC Data Sources], and contains a list of all the DSNs that the odbc.ini file defines. The parameters in this section are the names of the DSNs, which appear as section definitions later in the file. The value is a text description of the DSN and has no function. For example, an odbc.ini file that defines a single DSN named Vertica DSN could have this ODBC Data Sources section:

[ODBC Data Sources]
VerticaDSN = "vmartdb"

Appearing after the ODBC data sources section are sections that define each DSN. The name of a DSN section must match one of the names defined in the ODBC Data Sources section.

Configuring the odbc.ini file:

To create or edit the DSN definition file:

  1. Using the text editor of your choice, open odbc.ini or ~/.odbc.ini.

  2. Create an ODBC Data Sources section and define a parameter:

    • Whose name is the name of the DSN you want to create

    • Whose value is a description of the DSN

    For example, to create a DSN named VMart, you would enter:

    [ODBC Data Sources]
    VMart = "VMart database on Vertica"
    
  3. Create a section whose name matches the DSN name you defined in step 2. In this section, you add parameters that define the DSN's settings. The most commonly-defined parameters are:

    • Description – Additional information about the data source.

    • Driver – The location and designation of the Vertica ODBC driver, or the name of a driver defined in the odbcinst.ini file (see below). For future compatibility, use the name of the symbolic link in the library directory, rather than the library file:

      • ( /opt/vertica/lib, on 32-bit clients

      • /opt/vertica/lib64, on 64-bit clients

      For example, the symbolic link for the 64-bit ODBC driver library is:

      /opt/vertica/lib64/libverticaodbc.so
      

      The symbolic link always points to the most up-to-date version of the Vertica client ODBC library. Use this link so that you do not need to update all of your DSNs when you update your client drivers.

    • Database – The name of the database running on the server. This example uses vmartdb for the vmartdb.

    • ServerName — The name of the server where Vertica is installed. Use localhost if Vertica is installed on the same machine.

      You can provide an IPv4 address, IPv6 address, or host name.

      In mixed IPv4/IPv6 networks, the DNS server configuration determines which IP version address is sent first. Use the PreferredAddressFamily option to force the connection to use either IPv4 or IPv6.

    • UID — Either the database superuser (same name as database administrator account) or a user that the superuser has created and granted privileges. This example uses the user name dbadmin.

    • PWD —The password for the specified user name. This example leaves the password field blank.

    • Port — The port number on which Vertica listens for ODBC connections. For example, 5433.

    • ConnSettings — Can contain SQL commands separated by a semicolon. These commands can be run immediately after connecting to the server.

    • SSLKeyFile — The file path and name of the client's private key. This file can reside anywhere on the system.

    • SSLCertFile —The file path and name of the client's public certificate. This file can reside anywhere on the system.

    • Locale — The default locale used for the session. By default, the locale for the database is: en_US@collation=binary (English as in the United States of America). Specify the locale as an ICU Locale. See the ICU User Guide (http://userguide.icu-project.org/locale) for a complete list of parameters that can be used to specify a locale.

    • PreferredAddressFamily:

      The IP version to use if the client and server have both IPv4 and IPv6 addresses and you have provided a host name, one of the following:

      • ipv4: Connect to the server using IPv4.

      • ipv6: Connect to the server using IPv6.

      • none: Use the IP address provided by the DNS server.

For example:

[VMart]
Description = Vmart Database
Driver = /opt/vertica/lib64/libverticaodbc.so
Database = vmartdb
Servername = host01
UID = dbadmin
PWD =
Port = 5433
ConnSettings =
AutoCommit = 0
SSLKeyFile = /home/dbadmin/client.key
SSLCertFile = /home/dbadmin/client.crt
Locale = en_US@collation=binary

See ODBC DSN connection properties for a complete list of parameters including Vertica-specific ones.

Using an odbcinst.ini file

Instead of giving the path of the ODBC driver library in your DSN definitions, you can use the name of a driver defined in the odbcinst.ini file. This method is useful method if you have many DSNs and often need to update them to point to new driver libraries. It also allows you to set some additional ODBC parameters, such as the threading model.

Just as in the odbc.ini file, odbcinst.ini has sections. Each section defines an ODBC driver that can be referenced in the odbc.ini files.

In a section, you can define the following parameters:

  • Description— Additional information about the data source.

  • Driver— The location and designation of the Vertica ODBC driver, such as /opt/vertica/lib64/libverticaodbc.so

For example:

[Vertica]
Description = Vertica ODBC Driver
Driver = /opt/vertica/lib64/libverticaodbc.so

Then, in your odbc.ini file, use the name of the section you created in the odbcinst.ini file that describes the driver you want to use. For example:

[VMart]
Description = Vertica Vmart database
Driver = Vertica

If you are using the unixODBC driver manager, you should also add an ODBC section to override its standard threading settings. By default, unixODBC serializes all SQL calls through ODBC, which prevents multiple parallel loads. To change this default behavior, add the following to your odbcinst.ini file:

[ODBC]
Threading = 1

Configuring additional ODBC settings

On Linux and UNIX systems, you need to configure some additional driver settings before you can use your DSN. See ODBC driver settings for details.

2.1.4.4.1.1 - Testing an ODBC DSN using isql

The unixODBC driver manager includes a utility named isql, which is a simple ODBC command-line client.

The unixODBC driver manager includes a utility named isql, which is a simple ODBC command-line client. It lets you to connect to a DSN to send commands and receive results, similarly to vsql.

To use isql to test a DSN connection:

  1. Run the following command:

    $ isql –v DSNname
    

    Where DSNname is the name of the DSN you created.

    A connection message and a SQL prompt display. If they do not, you could have a configuration problem or you could be using the wrong user name or password.

  2. Try a simple SQL statement. For example:

    SQL> SELECT table_name FROM tables;
    

    The isql tool returns the results of your SQL statement.

2.1.4.4.2 - Creating an ODBC DSN for windows clients

To create a DSN for Microsoft Windows clients, you must perform the following tasks:.

To create a DSN for Microsoft Windows clients, you must perform the following tasks:

2.1.4.4.2.1 - Setting up an ODBC DSN

A Data Source Name (DSN) is the ODBC logical name for the drive and other information the database needs to access data.

A Data Source Name (DSN) is the ODBC logical name for the drive and other information the database needs to access data. The name is used by Internet Information Services (IIS) for a connection to an ODBC data source.

This section describes how to use the Vertica ODBC Driver to set up an ODBC DSN. This topic assumes that the driver is already installed, as described in Installing Client Drivers on Windows.

To set up a DSN

  1. Open the ODBC Administrator. For example, you could navigate to Start > Control Panel > Administrative Tools > Data Sources (ODBC).

  2. Decide if you want all users on your client system to be able to access to the DSN for the Vertica database.

    • If you want all users to have access, then click the System DSN tab.

    • Otherwise, click the User DSN tab to create a DSN that is only usable by your Windows user account.

  3. Click Add to create a new DSN to connect to the Vertica database.

  4. Scroll through the list of drivers in the Create a New Data Source dialog box to locate the Vertica driver. Select the driver, and then click Finish.

    The Vertica ODBC DSN configuration dialog box appears.

  5. Click the More >>> button to view a description of the field you are editing and the connection string defined by the DSN.

  6. Enter the information for your DSN. The following fields are required:

    • DSN Name — The name for the DSN. Clients use this name to identify the DSN to which they want to connect. The DSN name must satisfy the following requirements:

      • Its maximum length is 32 characters.

      • It is composed of ASCII characters except for the following: { } , ; ? * = ! @ \

      • It contains no spaces.

    • Server — The host name or IP address of the Vertica server to which you want to connect. Use localhost, if Vertica is installed on the same machine.

      You can provide an IPv4 address, IPv6 address, or host name.

      In mixed IPv4/IPv6 networks, the DNS server configuration determines which IP version address is sent first. Use the PreferredAddressFamily option to force the connection to use either IPv4 or IPv6.

      The PreferredAddressFamily option is available on the Client Settings tab.

    • Backup Servers — A comma-separated list of host names or IP addresses used to connect to if the server specified by the Server field is down. Optional.

    • Database —The name of the Vertica database.

    • User Name — The name of the user account to use when connecting to the database. If the application does not supply its own user name when connecting to the DSN, this account name is used to log into the database.

    The rest of the fields are optional. See DSN Parameters for detailed information about the DSN parameters you can define.

  7. If you want to test your connection:

    1. Enter at least a valid DSN name, Server name, Database, and either User name or select Windows authentication.

    2. If you have not selected Windows authentication, you can enter a password in the Password box. Alternately, you can select Password for missing password to have the driver prompt you for a password when connecting.

    3. Click Test Connection.

  8. When you have finished editing and testing the DSN, click OK. The Vertica ODBC DSN configuration window closes, and your new DSN is listed in the ODBC Data Source Administrator window.

  9. Click OK to close the ODBC Data Source Administrator.

After creating the DSN, you can test it using Microsoft Excel 2007.

Setting up a 32-Bit DSN on 64-Bit versions of Microsoft windows

On 64-bit versions of Windows, the default ODBC Data Source Administrator creates and edits DSNs that are associated with the 64-bit Vertica ODBC library.

Attempting to use these 64-bit DSNs with a 32-bit client application results in an architecture mismatch error. Instead, you must create a specific 32-bit DSN for 32-bit clients by running the 32-bit ODBC Administrator usually located at:

c:\Windows\SysWOW64\odbcad32.exe

This administrator window edits a set of DSNs that are associated with the 32-bit ODBC library. You can then use your 32-bit client applications with the DSNs you create with this version of the ODBC administrator.

2.1.4.4.2.2 - Encrypting passwords on ODBC DSN

When you install an ODBC driver and create a Data Source Name (DSN) the DSN settings are stored in the registry, including the password.

When you install an ODBC driver and create a Data Source Name (DSN) the DSN settings are stored in the registry, including the password. Encrypting passwords on ODBC DSN applies only to Windows systems.

Encrypting passwords on an ODBC data source name (DSN) provides security against unauthorized database access. The password is not encrypted by default and is stored in plain-text.

Enable password encryption

Use the EncryptPassword parameter to enable or disable password encryption for an ODBC DSN:

  • EncryptPassword = true enables password encryption

  • EncryptPassword = false (default) disables password encryption

Set EncryptPassword in the Windows registry - HKEY_LOCAL_MACHINE > Software > Vertica > ODBC > Driver EncryptPassword=<true/false>.

Encrypted passwords get updated in the following registry locations:

For a user DSN:

HKEY_CURRENT_USER-> Software -> ODBC -> ODBC.INI -> DSNNAME -> PWD

For a system DSN:

HKEY_LOCAL_MACHINE-> Software -> ODBC -> ODBC.INI -> DSNNAME -> PWD

Verify password encryption

Use Windows Registry editor to determine if password encryption is enabled based on the value of EncryptPassword. Depending on the type of DSN you installed, check the following:

For a user DSN: HKEY_CURRENT_USER > Software > ODBC > ODBC.INI > dsn name > isPasswordEncrypted=<1/0>

For a system DSN: HKEY_LOCAL_MACHINE > Software > ODBC > ODBC.INI > dsn name > isPasswordEncrypted=<1/0>

For each DSN, the value of the isPasswordEncrypted parameter indicates the status of the password encryption, where 1 indicates an encrypted password and 0 indicates an unencrypted password.

2.1.4.4.2.3 - Testing an ODBC DSN using Excel

You can use Microsoft Excel to verify that an application can connect to an ODBC data source or other ODBC application.

You can use Microsoft Excel to verify that an application can connect to an ODBC data source or other ODBC application.

  1. Open Microsoft Excel, and select Data > Get External Data > From Other Sources > From Microsoft Query.

  2. When the Choose Data Source dialog box opens:

    1. Select New Data Source, and click OK.

    2. Enter the name of the data source.

    3. Select the Vertica driver.

    4. Click Connect.

  3. When the Vertica Connection Dialog box opens, enter the connection information for the DSN, and click OK.

  4. Click OK on the Create New Data Source dialog box to return to the Choose Data Source dialog box.

  5. Select VMart_Schema*, and verify that the Use the Query Wizard check box is deselected. Click OK.

  6. When the Add Tables dialog box opens, click Close.

  7. When the Microsoft Query window opens, click the SQL button.

  8. In the SQL window, write any simple query to test your connection. For example:

    SELECT DISTINCT calendar_year FROM date_dimension;
    
  9. * If you see the caution, "SQL Query can't be represented graphically. Continue anyway?" click **OK**.      * The data values 2003, 2004, 2005, 2006, 2007 indicate that you successfully connected to and ran a query through ODBC.
    
  10. Select File > Return Data to Microsoft Office Excel.

  11. In the Import Data dialog box, click OK.

    The data is now available for use in an Excel worksheet.

2.1.4.4.3 - Creating an ODBC DSN for macOS clients

You can use the Vertica ODBC Driver to set up an ODBC DSN.

You can use the Vertica ODBC Driver to set up an ODBC DSN. This procedure assumes that the driver is already installed, as described in Installing the ODBC client driver.

Setting up a DSN

  1. Using your web browser, download and install the Apple ODBC Administrator Tool.

  2. Locate and open the ODBC Administrator Tool after installation:

    1. Navigate to Finder > Applications > Utilities.

    2. Open the ODBC Administrator Tool.

  3. Click the Drivers tab, and verify that the Vertica driver is installed.

  4. Specify if you want all users on your client system to be able to access the DSN for the Vertica database:

    • If you want all users to have access, then click the System DSN tab.

    • Otherwise, click the User DSN tab to create a DSN that is only usable by your Macintosh user account.

  5. Click Add... to create a new DSN to connect to the Vertica database.

  6. Scroll through the list of drivers in the Choose A Driver dialog box to locate the Vertica driver. Select the driver, and then click OK. A dialog box opens that requests DSN parameter information.

  7. In the dialog box, enter the Data Source Name (DSN) and an optional Description. To do so, click Add to insert keywords (parameters) and values that define the settings needed to connect to your database, including database name, server host, database user name (such as dbadamin), database password, and port. Then, click OK.

  8. In the ODBC Administrator dialog box, click Apply.

    See ODBC DSN connection properties for a complete list of parameters including those specific to Vertica.

After configuring the ODBC Administrator Tool, you may need to configure additional driver settings before you can use your DSN, depending on your environment. See Additional ODBC Driver Configuration Settings for details.

2.1.4.4.3.1 - Testing an ODBC DSN using iodbctest

The standard iODBC Driver Manager on OS X includes a utility named iodbctest that lets you test a DSN to verify that it is correctly configured.

The standard iODBC Driver Manager on OS X includes a utility named iodbctest that lets you test a DSN to verify that it is correctly configured. You pass this command a connection string in the same format that you would use to open an ODBC database connection. After configuring your DSN connection, you can run a query to verify that the connection works.

For example:


# iodbctest "DSN=VerticaDSN;UID=dbadmin;PWD=password"
iODBC Demonstration program
This program shows an interactive SQL processor
Driver Manager: 03.52.0607.1008
Driver: 07.01.0200 (verticaodbcw.so)
SQL> SELECT table_name FROM tables;
table_name
--------------------------------------------------------------------------------------------------------------------------------
customer_dimension
product_dimension
promotion_dimension
date_dimension
vendor_dimension
employee_dimension
shipping_dimension
warehouse_dimension
inventory_fact
store_dimension
store_sales_fact
store_orders_fact
online_page_dimension
call_center_dimension
online_sales_fact
numbers
result set 1 returned 16 rows.

2.1.4.4.4 - ODBC DSN connection properties

The following tables list the connection properties you can set in the DSNs for use with Vertica's ODBC driver.

The following tables list the connection properties you can set in the DSNs for use with Vertica's ODBC driver. To set these parameters, see Setting DSN connection properties.

Required connection properties

These connection properties are the minimum required to create a functioning DSN.

Property Description
Driver The file path and name of the driver used.
Database The name of the database running on the server.
Servername

The host name or IP address of any active node in a Vertica cluster.

You can provide an IPv4 address, IPv6 address, or host name.

In mixed IPv4/IPv6 networks, the DNS server configuration determines which IP version address is sent first. Use the PreferredAddressFamily option to force the connection to use either IPv4 or IPv6.

You can also use the aliases "server" and "host" for this property.

UID The database username.

Optional properties

Property Description
Port

The port number on which Vertica listens for ODBC connections.

Default: 5433

PWD

The password for the specified user name. You may insert an empty string to leave this property blank.

Default: None, login only succeeds if the user does not have a password set.

PreferredAddressFamily

The IP version to use if the client and server have both IPv4 and IPv6 addresses and you have provided a host name, one of the following:

  • ipv4: Connect to the server using IPv4.

  • ipv6: Connect to the server using IPv6.

  • none: Use the IP address provided by the DNS server.

Default: none

Advanced settings

Property Description
AutoCommit

A Boolean value that controls whether the driver automatically commits transactions after executing a DML statement.

Default: true

BackupServerNode

A string containing the host name or IP address that client libraries can try to connect to if the host specified in ServerName is unreachable. Connection attempts continue until successful or until the list of server nodes is exhausted.

Valid values: Comma-separated list of servers optionally followed by a colon and port number.

ConnectionLoadBalance

A Boolean value that indicates whether the connection can be redirected to a host in the database other than the ServerNode.

This affects the connection only if the load balancing. is set to something other than "none". When the node differs from the node the client is connected to, the client disconnects and reconnects to the targeted node. See About Native Connection Load Balancing in the Administration Guide.

Default: false

ConnSettings

A string containing SQL commands that the driver should execute immediately after connecting to the server. You can use this property to configure the connection, such as setting a schema search path.

Reserved symbol: In the connection string semicolon (;) is a reserved symbol. To set multiple properties as part of ConnSettings properties, use %3B as the comma delimiter, and + (plus) for spaces.

ConnectionTimeout

The number of seconds to wait for a request to complete before returning to the client application. This is equivalent to the SQL_ATTR_CONNECTION_TIMEOUT parameter in the ODBC API.

Default: 0 (no timeout)

ConvertSquareBracketIdentifiers

Controls whether square-bracket query identifiers are converted to a double quote identifier for compatibility when making queries to a Vertica database.

Default: false

DirectBatchInsert Deprecated, always set to true.
DriverStringConversions

Controls whether the ODBC driver performs type conversions on strings sent between the ODBC driver and the database. Possible values are:

  • NONE: No conversion in either direction. This results in the highest performance.

  • INPUT: Strings sent from the client to the server are converted, but strings sent from the server to the client are not.

  • OUTPUT: Strings sent by the server to the client are converted, but strings sent from the client to the server are not.

  • BOTH: Strings are converted in both directions.

Default: OUTPUT

Locale

The locale used for the session. Specify the locale as an ICU Locale.

**See **the ICU User Guide for a complete list of properties that can be used to specify a locale.

Default: en_US@collation=binary

PromptOnNoPassword

[Windows only] Controls whether users are prompted to enter a password, if none is supplied by the connection string or DSN used to connect to Vertica. See Prompting windows users for passwords.

Default: false

ReadOnly

A true or false value that controls whether the connection can read data only from Vertica.

Default: false

ResultBufferSize

Size of memory buffer for the large result sets in streaming mode. A value of 0 means ResultBufferSize is turned off.

Default: 131072 (128KB)

TransactionIsolation

Sets the transaction isolation for the connection, one of the following:

  • Read Committed

  • Serializable

  • Server Default

See Changing Transaction Isolation Levels for an explanation of transaction isolation.

Default: Server Default

Workload

The name of the workload for the session. For details, see Workload routing.

Default: None (no workload)

Identification

Property Description Standard/ Vertica
Description

Description for the DSN entry.

Required? No

Insert an empty string to leave the description empty.

Standard
Label / SessionLabel

Sets a label for the connection on the server. This value appears in the client_label column of the V_MONITOR.SESSIONS system table.

Label and SessionLabel are synonyms and can be used interchangeably.

Vertica

OAuth connection properties

The following connection properties pertain to OAuth in ODBC.

Property Description
OAuthAccessToken

Required if OAuthRefreshToken is unspecified, an OAuth token that authorizes a user to the database.

Either OAuthAccessToken or OAuthRefreshToken must be set (programmatically or manually) to authenticate to Vertica with OAuth authentication.

You can omit both OAuthAccessToken and OAuthRefreshToken only if you authenticate to your identity provider directly with single sign-on through the client driver, which requires the machine running the ODBC driver to have access to a web browser.

For details on the different methods for retrieving access tokens, see Retrieving access tokens.

OAuthRefreshToken Required if OAuthAccessToken is unspecified, a token that used to obtain a new access token when their old one expires.

Either OAuthAccessToken or OAuthRefreshToken must be set (programmatically or manually) to authenticate to Vertica with OAuth authentication.

You can omit both OAuthAccessToken and OAuthRefreshToken only if you authenticate to your identity provider directly with single sign-on through the client driver, which requires the machine running the ODBC driver to have access to a web browser.

For details on the different methods for retrieving access tokens, see Retrieving access tokens.

If you set this parameter, you must also set the OAuthClientSecret connection property.

In cases where introspection fails (e.g. when the access token expires), Vertica responds to the request with an error. If introspection fails and OAuthRefreshToken is specified, the driver attempts to refresh and silently retrieve a new access token. Otherwise, the driver passes error to the client application.

OAuthClientSecret The secret provided by your identity provider for your client. This parameter is required for confidential clients.

Encryption

Property Description Standard/ Vertica
SSLMode

Controls whether the connection to the database uses SSL encryption, one of the following. For information on using these parameters to configure TLS, see Configuring TLS for ODBC Clients:

  • require: Requires that the server use TLS. If the TLS connection attempt fails, the client rejects the connection.
  • prefer: Prefers that the server use TLS. The client first attempts to connect using TLS. If that attempt fails, the client attempts to connect again in plaintext.
  • allow: Makes a connection to the server whether the server uses TLS or not. The first connection attempt to the database is attempted over a clear channel. If that fails, a second connection is attempted over TLS.
  • verify_ca: The client verifies that the server's certificate was issued by a trusted certificate authority (CA).
  • verify_full: The client verifies that the following conditions are met:
  • The server's certificate was issued by a trusted CA.
  • One of the following:
    • The server's hostname matches the common name specified in the server's certificate.
    • The server's hostname or IP address appears in the Subject Alternative Name (SAN) field of the server's certificate.
  • disable: Never connect to the server using TLS. This setting is typically used for troubleshooting.

Default: prefer

Vertica
SSLCertFile The absolute path of the client's public certificate file. This file can reside anywhere on the system. Vertica
SSLKeyFile The absolute path to the client's private key file. This file can reside anywhere on the system. Vertica

Third-party compatibility

Property Description Default Standard/ Vertica
ColumnsAsChar

Specifies how character column types are reported when the driver is in Unicode mode. When set to false, the ODBC driver reports the data type of character columns as WCHAR. If you set ColumnsAsChar to true, the driver identifies character column as CHAR.

You typically use this setting for compatibility with some third-party clients.

Default: false

false Vertica
ThreePartNaming

A Boolean value that controls how catalog names are interpreted by the driver. When this value is false, the driver reports that catalog names are not supported. When catalog names are not supported, they cannot be used as a filter in database metadata API calls. In this case, the driver returns NULL as the catalog name in all driver metadata results.

When this value is true, catalog names can be used as a filter in database metadata API calls. In this case, the driver returns the database name as the catalog name in metadata results. Some third-party applications assume a certain catalog behavior and do not work properly with the default values. Enable this option if your client software expects to get the catalog name from the database metadata and use it as part of a three-part name reference.

Default: false for UNIX, true for Windows

false (UNIX)

true (Window)

Vertica
EnforceBatchInsertNullConstraints

Prevents NULL values from being loaded into columns with a NOT NULL constraint during batch inserts. When this value is set to true, batch inserts roll back when NULL values are inserted in to columns with NOT NULL constraints. When this value is set to false, batch insert behavior is unchanged.

Vertica recommends only using this property with SAP Data Services as it could negatively impact database performance.

false Vertica

Kerberos connection properties

Use the following properties for client authentication using Kerberos.

Property Description Standard/ Vertica
KerberosServiceName

Provides the service name portion of the Vertica Kerberos principal; for example: vertichost@EXAMPLE.COM

Default: vertica

Vertica
KerberosHostname

Provides the instance or host name portion of the Vertica Kerberos principal; for example: verticaosEXAMPLE.COM

Default: Value specified in the servername connection string property

Vertica

See also

ODBC driver settings

2.1.4.4.5 - Setting DSN connection properties

The properties in the following tables are common for all user and system DSN entries.

The properties in the following tables are common for all user and system DSN entries. The examples provided are for Windows clients.

To edit DSN properties:

  • On UNIX and Linux client platforms, you can edit the odbc.ini file. The location of this file is specific to the driver manager. See Creating an ODBC DSN for Linux.

  • On Windows client platforms, you can edit some DSN properties using the Vertica ODBC client driver interface. See Creating an ODBC DSN for windows clients.

  • You can also edit the DSN properties directly by opening the DSN entry in the Windows registry (for example, at HKEY_LOCAL_MACHINE\SOFTWARE\ODBC\ODBC.INI\DSNname). Directly editing the registry can be risky, so you should only use this method for properties that cannot be set through the ODBC driver's user interface, or via your client code.

  • You can set properties in the connection string when opening a connection using the SQLDriverConnect() function:

    sqlRet = SQLDriverConnect(sql_hDBC, 0, (SQLCHAR*)"DSN=DSNName;Locale=en_GB@collation=binary", SQL_NTS, szDNS, 1024,&nSize, SQL_DRIVER_NOPROMPT);
    
  • Your client code can retrieve DSN property values after a connection has been made to Vertica using the SQLGetConnectAttr() and SQLGetStmtAttr() API calls. Some properties can be set and using SQLSetConnectAttr() and SQLSetStmtAttr().

    For details of the list of properties specific to Vertica see ODBC Header Files specific to Vertica.

2.1.4.5 - ODBC driver settings

While required settings are required for all platforms, these settings automatically set by the Windows and macOS installers, so all directives to change these settings are for Linux users.
  • DriverManagerEncoding: The UTF encoding standard used by the driver manager. This can be one of the following:

    • UTF-8

    • UTF-16

    • UTF-32

    The ODBC driver encoding must match that of your driver manager. The following table lists default encodings for various platforms that take effect if you do not set this parameter. If the defaults do not match the encoding used by your driver manager, you must set it manually. Consult your driver manager's documentation for details on its encoding.

    Client Platform Default Encoding
    Linux 32-bit UTF-32
    Linux 64-bit UTF-32
    Linux Itanium 64-bit UTF-32
    OS X UTF-32
    Windows 32-bit UTF-16
    Windows 64-bit UTF-16
  • ErrorMessagesPath: Required, the path of the directory containing the ODBC driver's error message files. These files (ODBCMessages.xml and VerticaMessages.xml) are stored in the same directory as the Vertica ODBC driver files (for example, opt/vertica/en-US in the downloaded .tar).

  • ODBCInstLib: The path to the ODBC installer library. This setting is only required if the directory containing the library is not set in the LD_LIBRARY_PATH or LIB_PATH environment variables. The library files for the major driver managers are:

  • UnixODBC: libodbcinst.so

  • iODBC: libiodbcinst.so (libiodbcinst.2.dylib on macOS)

  • DataDirect: libodbcinst.so

You can also control client-server message logging for both ODBC and ADO.NET. For details, see Configuring ODBC logs.

Linux and macOS

To set these parameters on Linux or macOS:

  1. Create a file vertica.ini anywhere on the client system. Common locations are in /etc/ for a shared configuration, or the home directory for a per-user configuration.

  2. Verify that users of the ODBC driver have read privileges on the file.

  3. Set the VERTICAINI environment variable to the path of vertica.ini. For example:

$ export VERTICAINI=/etc/vertica.ini
  1. Create a section called [Driver] in vertica.ini:
[Driver]
  1. Under [Driver], set parameters with the following format. Each parameter must have its own line:
[Driver]
DriverManagerEncoding=UTF-16
ODBCInstLib=/usr/lib64/libodbcinst.so

Windows

The Windows client driver installer automatically configures all necessary settings for the ODBC driver. Settings are stored in the registry in HKEY_LOCAL_MACHINE\SOFTWARE\Vertica\ODBC\Driver.

If you want to configure ODBC further, use the ODBC Data Sources program.

2.1.4.6 - Configuring ODBC logs

The following parameters control whether and how the ODBC client driver logs messages between the client and server.

The following parameters control whether and how the ODBC client driver logs messages between the client and server.

The way you set these parameters differs between operating systems:

  • On Linux and macOS, edit vertica.ini you created during the installation. For example, to log all warnings and more severe messages to log files in /tmp/:

    [Driver]
    LogLevel=4
    LogPath=/tmp
    
  • On Windows, edit the keys in the Windows Registry under HKEY_LOCAL_MACHINE\SOFTWARE\Vertica\ODBC\Driver.

Parameters

  • LogLevel: The severity of messages that are logged between the client and the server. The valid values are:

    • 0: No logging

    • 1: Fatal errors

    • 2: Errors

    • 3: Warnings

    • 4: Info

    • 5: Debug

    • 6: Trace (all messages)

    The value you specify for this setting sets the minimum severity for a message to be logged. For example, setting LogLevel to 3 means that the client driver logs all warnings, errors, and fatal errors.

  • LogPath: The absolute path of a directory to store log files. For example: /var/log/verticaodbc

Diverting log entires to ETW (windows)

On Windows clients, ODBC log entries can be sent to Event Tracing for Windows (ETW) so they appear in the Windows Event Viewer:

  • Register the driver as a Windows Event Log provider and enable the logs.

  • Activate ETW by adding a string value LogType with data ETW to your Windows Registry.

  • Understand how Vertica compresses log levels for the Windows Event Viewer.

  • Know where to find the logs within Event Viewer.

  • Understand the meaning of the Event IDs in your log entries.

Registering the ODBC driver as a windows event log provider

To use ETW logging, you must register the ODBC driver as a Windows Event Log provider. You can choose to register either the 32-bit or 64-bit driver. After you have registered the driver, you must enable the logs.

  1. Open a command prompt window as Administrator, or launch the command prompt with the Run as Administrator option.

  2. Run the command wevtutil im to register either the 32-bit or 64-bit version of the driver.

    • For the 64-bit ODBC driver, run:

      wevtutil im "c:\Program Files\Vertica Systems\ODBC64\lib\VerticaODBC64.man"
      /resourceFilePath:"c:\Program Files\Vertica Systems\ODBC64\lib\vertica_9.1_odbc_3.5.dll"
      /messageFilePath:"c:\Program Files\Vertica Systems\ODBC64\lib\vertica_9.1_odbc_3.5.dll"
      
    • For the 32-bit ODBC driver, run:

      wevtutil im "c:\Program Files (x86)\Vertica Systems\ODBC32\lib\VerticaODBC32.man"
      /resourceFilePath:"c:\Program Files (x86)\Vertica Systems\ODBC32\lib\vertica_9.1_odbc_3.5.dll"
      /messageFilePath:"c:\Program Files (x86)\Vertica Systems\ODBC32\lib\vertica_9.1_odbc_3.5.dll"
      
  3. Run the command wevtutil sl to enable the logs.

    • For 64-bit ODBC driver logs, run:

      wevtutil sl VerticaODBC64/e:true
      
    • For the 32-bit ODBC driver logs, run:

      wevtutil sl VerticaODBC32/e:true
      

Add the string value LogType

By default, Vertica does not send ODBC log entries to ETW. To activate ETW, add the string LogType to your Windows registry, and set its value to ETW.

  1. Start the registry editor by typing regedit.exe in the Windows Run command box.

  2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Vertica\ODBC\Driver in the registry.

  3. Right-click in the right pane of the Registry Editor window.

  4. Select New, then select String Value.

  5. Change the name of the string value from New Value #1 to LogType.

  6. Double-click the new LogType entry. When prompted for a new value, enter ETW.

  7. Exit the registry editor.

ETW is disabled by default. When ETW is enabled, you can disable it by clearing the value ETW from the LogType string.

LogLevel in the windows event viewer

While LogLevel ranges from 0 through 6, this range is compressed for the Windows Event Viewer to a range of 0 through 3.

Vertica LogLevel Setting Vertica LogLevel Description Log level sent to the Windows Event Viewer Log level displayed by the Windows Event Viewer
0 (No logging) 0 (No logging)
1 Fatal Errors 1 Critical
2 Errors 2 Error
3 Warnings 3 Warning
4 Info 4 Information
5 Debug 4
6 Trace (all messages) 4

The following examples show how LogLevel is converted when displayed in the Windows Event Viewer.

  • A LogLevel of 5 sends fatal errors, errors, warnings, info and debug log level entries to Event Viewer as Level 4 (Information).

  • A LogLevel of 6 sends fatal errors, errors, warnings, debug and trace log level entries to Event Viewer as Level 4.

Finding logs in the event viewer

  1. Launch the Windows Event Viewer.

  2. From Event Viewer (Local), expand Applications and Services Logs.

  3. Expand the folder that contains the log you want to review (for example, VerticaODBC64).

  4. Select the Vertica ODBC log under the folder. Entries appear in the right pane.

  5. Note the value in the Event ID field. Each Event Log entry includes one of four Event IDs:

    • 0: Informational (debug, info, and trace events)

    • 1: Error

    • 2: Fatal event

    • 3: Warning

2.1.5 - Python client drivers

Vertica supports several Python drivers for creating client applications.

Vertica supports several Python drivers for creating client applications.

Prerequisites

To create Python client applications, you must install the required drivers.

2.1.5.1 - Installing Python client drivers

Vertica supports several Python client drivers.

Vertica supports several Python client drivers.

Installing vertica-python

See the vertica-python repository for installation and usage instructions.

Installing pyodbc

The pyodbc module interacts with the Vertica ODBC client driver. To install it:

  1. Install the ODBC client driver.

  2. Install compatible versions of Python and pyodbc.

2.1.6 - Node.js client driver

The open-source vertica-nodejs client driver lets you interact with your database with JavaScript.

The open-source vertica-nodejs client driver lets you interact with your database with JavaScript. For details, see the vertica-nodejs package on npm.

2.1.7 - Go client driver

The open-source vertica-sql-go driver lets you interact with your database with Go.

The open-source vertica-sql-go driver lets you interact with your database with Go. For details, see vertica-sql-go.

2.1.8 - OLE DB client driver

The OLE DB client driver is an interface for Microsoft Analysis Services (SSAS) and C# client applications to interact with your Vertica database.

The OLE DB client driver is an interface for C# client applications to interact with your Vertica database.

2.1.8.1 - Installing the OLE DB client driver

To install the Vertica OLE DB client driver:.

To install the Vertica OLE DB client driver:

  1. Download the Windows client driver installer. For details on the drivers included in this installer, see Windows client driver installer.

  2. Run the installer and follow the prompts to install the drivers.

  3. Reboot your system.

After installing the OLE DB client driver, you can configure ETW logging.

For a list of connection properties, see OLE DB connection properties.

2.1.8.1.1 - OLE DB connection properties

Use the Connection Manager to set the OLE DB connection string properties, which define your connection.

Use the Connection Manager to set the OLE DB connection string properties, which define your connection. You access the Connection Manager from within Visual Studio.

These connection parameters appear on the Connection page.

Parameters Action
Provider Select the native OLE DB provider for the connection.
OLE DB Provider Indicates Vertica OLE DB Provider.
Server or file name Enter the server or file name.
Location Not supported.
Use Windows NT Integrated Security Not supported.
Use a specific user name and password

Enter a user name and password.

Connect with No Password:

Select the Blank password check box.

Save and Encrypt Password:

Select Allow saving password.

Initial Catalog The name of the database running on the server.

The All page from the Connection Manager dialog box includes all possible connection string properties for the provider.

The table that follows lists the connection parameters for the All page.

For OLE DB properties information specific to Microsoft, see the Microsoft documentation OLE DB Properties.

Parameters Action
Extended Properties Not supported.
Locale Identifier

Indicates the Locale ID.

Default: 0

Mode

Specifies access permissions.

Default: 0

Connect Timeout

Not supported.

Default: 0

General Timeout Not supported.
File Name Not supported.
OLE DB Services Specifies which OLE DB services to enable or disable.
Password

Specifies the password for the user ID.

For no password, insert an empty string.

Persist Security Info

A security measure. When False, security sensitive-information, such as the password, is not returned as part of the connection if the connection is open or has ever been in an open state.

Default: true

User ID The database username.
Data Source

The host name or IP address of any active node in a Vertica cluster.

You can provide an IPv4 address, IPv6 address, or host name.

In mixed IPv4/IPv6 networks, the DNS server configuration determines which IP version address is sent first. Use the PreferredAddressFamily option to force the connection to use either IPv4 or IPv6.

Initial Catalog The name of the database running on the server.
Provider

The name of the OLE DB Provider to use when connecting to the Data Source.

Default: VerticaOLEDB.1

BackupServerNode

A designated host name or IP address to use if the ServerName host is unavailable. Enter as a string.

Connection attempts continue until successful or until the list of server nodes is exhausted.

Valid values: Comma-separated list of servers optionally followed by a colon and port number. For example:

server1:5033,server2:5034

ConnectionLoadBalance

A Boolean value that determines whether the connection can be redirected to a host in the database other than the ServerNode.

This parameter affects the connection only if load balancing is set to a value other than NONE. When the node differs from the node that the client is connected to, the client disconnects and reconnects to the targeted node. See About Native Connection Load Balancing in the Administration Guide.

Default: false

ConnSettings

SQL commands that the driver should execute immediately after connecting to the server. Use to configure the connection, such as setting a schema search path.

Reserved symbol:';' To set multiple parameters in this field use '%3B' for ','.

Spaces: Use '+'.

ConvertSquareBracketIdentifiers

Controls whether square-bracket query identifiers are converted to a double quote identifier for compatibility when making queries to a Vertica database.

Default: false

DirectBatchInsert Deprecated, always set to true.
KerberosHostName Provides the instance or host name portion of the Vertica Kerberos principal; for example: verticaosEXAMPLE.COM
KerberosServiceName Provides the service name portion of the Vertica Kerberos principal; for example: vertichost@EXAMPLE.COM
Label Sets a label for the connection on the server. This value appears in the session_id column of system table SESSIONS .
LogLevel Specifies the amount of information included in the log. Leave this field blank or set to 0 unless otherwise instructed by Vertica Customer Support.
LogPath The path for the log file.
Port

The port number on which Vertica listens for OLE DB connections.

Default: port 5433

PreferredAddressFamily

The IP version to use if the client and server have both IPv4 and IPv6 addresses and you have provided a host name, one of the following:

  • ipv4: Connect to the server using IPv4.

  • ipv6: Connect to the server using IPv6.

  • none: Use the IP address provided by the DNS server.

SSLCertFile The absolute path of the client's public certificate file. This file can reside anywhere on the system.
SSLKeyFile The absolute path to the client's private key file. This file can reside anywhere on the system.
SSLMode

Controls whether the connection to the database uses SSL encryption, one of the following:

  • require: Requires the server to use SSL. If the server cannot provide an encrypted channel, the connection fails.

  • prefer: Prefers that the server use SSL. If the server does not offer an encrypted channel, the client requests one. The first attempt is made with SSL. If that attempt fails, the second attempt is over a clear channel.

  • allow: Makes a connection to the server whether or not the server uses SSL. The first attempt is made over a clear channel. If that attempt fails, a second attempt is over SSL.

  • disable: Never connects to the server using SSL. Typically, you use this setting for troubleshooting.

Default: prefer

2.1.8.1.2 - Configuring OLE DB logs

The following parameters control how the OLE DB client driver logs messages between the client and server.

The following parameters control how the OLE DB client driver logs messages between the client and server. To set them, edit the keys in the Windows Registry under HKEY_LOCAL_MACHINE\SOFTWARE\Vertica\OLEDB\Driver:

  • LogLevel: The severity of messages that are logged between the client and the server. The valid values are:

    • 0: No logging

    • 1: Fatal errors

    • 2: Errors

    • 3: Warnings

    • 4: Info

    • 5: Debug

    • 6: Trace (all messages)

    The value you specify for this setting sets the minimum severity for a message to be logged. For example, setting LogLevel to 3 means that the client driver logs all warnings, errors, and fatal errors.

  • LogPath: The absolute path of a directory to store log files. For example: /var/log/verticaoledb

Diverting OLE DB log entries to ETW

On Windows clients, you can direct Vertica to send OLE DB log entries to Event Tracing for Windows (ETW). Once set, OLE DB log entries appear in the Windows Event Viewer. To use ETW:

  • Register the driver as a Windows Event Log provider, and enable the logs.

  • Activate ETW by adding a string value to your Windows Registry.

  • Understand how Vertica compresses log levels for the Windows Event Viewer.

  • Know where to find the logs within Event Viewer.

  • Understand the meaning of the Event IDs in your log entries.

Registering the OLE DB driver as a windows event log provider

To use ETW logging, you must register the OLE DB driver as a Windows Event Log provider. You can choose to register either the 32-bit or 64-bit driver. Once you have registered the driver, you must enable the logs.

  1. Open a command prompt window as Administrator, or launch the command prompt with the Run as Administrator option.

  2. Run the command wevtutil im to register either the 32-bit or 64-bit version of the driver.

    1. For the 64-bit OLE DB driver, run:

      wevtutil im "c:\Program Files\Vertica Systems\OLEDB64\lib\VerticaOLEDB64.man"
      /resourceFilePath:"c:\Program Files\Vertica Systems\OLEDB64\lib\vertica_8.1_oledb.dll"
      /messageFilePath:"c:\Program Files\Vertica Systems\OLEDB64\lib\vertica_8.1_oledb.dll"
      
    2. For the 32-bit OLE DB driver, run:

      wevtutil im "c:\Program Files (x86)\Vertica Systems\OLEDB32\lib\VerticaOLEDB32.man"
      /resourceFilePath:"c:\Program Files (x86)\Vertica Systems\OLEDB32\lib\vertica_8.1_oledb.dll"
      /messageFilePath:"c:\Program Files (x86)\Vertica Systems\OLEDB32\lib\vertica_8.1_oledb.dll"
      
  3. Run the command wevtutil sl to enable the logs.

    1. For 64-bit OLE DB driver logs, run:

      wevtutil sl VerticaOLEDB64/e:true
      
    2. For the 32-bit ODBC driver logs, run:

      wevtutil sl VerticaOLEDB32/e:true
      

Add the string value LogType

By default, Vertica does not send OLE DB log entries to ETW. To activate ETW, add the string LogType to your Windows registry, and set its value to ETW.

  1. Start the registry editor by typing regedit.exe in the Windows Run command box.

  2. Navigate, in the registry, to: HKEY_LOCAL_MACHINE\SOFTWARE\Vertica\OLEDB\Driver.

  3. Right-click in the right pane of the Registry Editor window.

  4. Select New, then select String Value.

  5. Change the name of the string value from New Value #1 to LogType.

  6. Double-click the new LogType entry. When prompted for a new value, enter ETW.

  7. Exit the registry editor.

ETW is off by default. When ETW is activated, you can subsequently turn it off by clearing the value ETW from the LogType string.

LogLevel in the windows event viewer

While LogLevel ranges from 0 through 6, this range is compressed for the Windows Event Viewer to a range of 0 through 3.

Vertica LogLevel Setting Vertica LogLevel Description Log level sent to the Windows Event Viewer Log level displayed by the Windows Event Viewer
0 (No logging) 0 (No logging)
1 Fatal Errors 1 Critical
2 Errors 2 Error
3 Warnings 3 Warning
4 Info 4 Information
5 Debug 4
6 Trace (all messages) 4

The following examples show how LogLevel is converted when displayed in the Windows Event Viewer.

  • A LogLevel of 5 sends fatal errors, errors, warnings, info and debug log level entries to Event Viewer as Level 4 (Information).

  • A LogLevel of 6 sends fatal errors, errors, warnings, debug and trace log level entries to Event Viewer as Level 4.

Finding logs in the event viewer

  1. Launch the Windows Event Viewer.

  2. From Event Viewer (Local), expand Applications and Services Logs.

  3. Expand the folder that contains the log you want to review (for example, VerticaOLEDB64).

  4. Select the Vertica ODBC log under the folder. Entries appear in the right pane.

  5. Note the value in the Event ID field. Each Event Log entry includes one of four Event IDs:

    • 0: Informational (debug, info, and trace events)

    • 1: Error

    • 2: Fatal event

    • 3: Warning

2.1.9 - ADO.NET client driver

The Vertica ADO.NET driver lets you access with C#.

The Vertica ADO.NET driver lets you access Vertica with C# .

2.1.9.1 - Installing the ADO.NET client driver

The ADO.NET client driver requires the following:.

Prerequisites

The ADO.NET client driver requires the following:

Installation

For a sample application that uses and demonstrates all of these installation methods, see the client-application-examples repository.

Package reference

The ADO.NET client driver is available on NuGet and should be installed with a package reference.

To reference the package, add the following to your .csproj. For an example .csproj file, see SampleApp.csproj:

<ItemGroup>
  <PackageReference Include="Vertica.Data" Version="24.1.0" />
</ItemGroup>

Local package reference

You can also download the Vertica.Data package and reference it locally.

On Windows platforms, you can install the ADO.NET driver with the Windows installer and then reference the .dll. This is required for certain applications like TIBCO Spotfire to interact with the driver:

<ItemGroup>
  <Reference Include="Vertica.Data">
    <HintPath>path\to\Program Files\Vertica Systems\ADO.NET64\Vertica.Data.dll</HintPath>
  </Reference>
</ItemGroup>

2.1.9.2 - Log properties

The following parameters control how messages between the client and server are logged. If they are not set, then the client library does not log any messages.

Config-level Settings

The following parameters control how messages between the client and server are logged. If they are not set, then the client library does not log any messages.

To set these parameters, create and edit the configuration file Vertica.Data.dll.config in one of the following locations. If the file exists in both locations, the one in the home directory takes priority:

  • Home directory
  • Project directory
LogLevel
The minimum severity of a message for it to be logged, one of the following:
  • 0: No logging
  • 1: Fatal errors
  • 2: Errors
  • 3: Warnings
  • 4: Info
  • 5: Debug
  • 6: Trace (all messages)

For example, a LogLevel of 3 means that the client driver logs messages with severities 1, 2, and 3.

LogPath
The absolute path of the log file. For example: /var/log/verticaadonet/ado.log.
LogNamespace
Limits logging to messages generated by certain objects in the client driver.

Example configuration file

The following example configuration file uses the default values for each configuration setting:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <appSettings>
        <add key="Logging.LogLevel" value="None" />
        <add key="Logging.LogPath" value="" />
        <add key="Logging.LogNamespace" value="" />
    </appSettings>
</configuration> 

VerticaLogProperties

You can set the log properties of the ADO.NET driver with the VerticaLogProperties class, which includes the following methods:

  • SetLogPath(String path)
  • SetLogNamespace(String lognamespace)
  • SetLogLevel(VerticaLogLevel loglevel)

Logs are created when the first connection is opened, so you cannot change the log path with SetLogPath() after the connection starts. You can change the log level and log namespace at any time.

Changes made by these functions last for the lifetime of the application. To make permanent changes, use Vertica.Data.dll.config.

SetLogPath()

The SetLogPath() method takes as an argument a String path containing the path to the log file. If the path string contains only a directory path, then the log file is created with the name vdp-driver-MM-dd_HH.mm.ss.log (where MM-dd_HH.mm.ss is the date and time the log was created). If the path ends in a filename, such as log.txt or log.log, then the log is created with that filename.

If SetLogPath() is called with an empty string for the path argument, then the client executable's current directory is used as the log path.

If SetLogPath() is not called and entry exists for the log path in Vertica.Data.dll.config, and you have called any of the other VerticaLogProperties methods, then the client executable's current directory is used as the log path.

For example:

//set the log path
string path = "C:\\log";
VerticaLogProperties.SetLogPath(path);

SetLogNamespace()

The SetLogNamespace() method takes as an argument a String lognamespace containing the namespace to log. The namespace string to log can be one of the following:

  • Vertica
  • Vertica.Data.VerticaClient
  • Vertica.Data.Internal.IO
  • Vertica.Data.Internal.DataEngine
  • Vertica.Data.Internal.Core

Namespaces can be truncated to include child namespaces. For example, you can specify Vertica.Data.Internal to log for all of the Vertica.Data.Internal namespaces.

If a log namespace is not set, and no value is stored in Vertica.Data.dll.config, then the Vertica namespace is used for logging.

For example:

//set namespace to log
string lognamespace = "Vertica.Data.VerticaClient";
VerticaLogProperties.SetLogNamespace(lognamespace);

SetLogLevel()

The SetLogLevel() method takes as an argument a VerticaLogLevel loglevel, one of the following:

  • VerticaLogLevel.None
  • VerticaLogLevel.Fatal
  • VerticaLogLevel.Error
  • VerticaLogLevel.Warning
  • VerticaLogLevel.Info
  • VerticaLogLevel.Debug
  • VerticaLogLevel.Trace

If a log level is not set, and no value is stored in Vertica.Data.dll.config, then VerticaLogLevel.None is used.

For example:

//set log level
VerticaLogLevel level = VerticaLogLevel.Debug;
VerticaLogProperties.SetLogLevel(level);

Getting log properties

You can retrieve the values for the following properties with the VerticaLogProperties class:

  • LogPath
  • LogNamespace
  • LogLevel

For example:

//get current log settings
string logpath = VerticaLogProperties.LogPath;
VerticaLogLevel loglevel = VerticaLogProperties.LogLevel;
string logns = VerticaLogProperties.LogNamespace;
Console.WriteLine("Current Log Settings:");
Console.WriteLine("Log Path: " + logpath);
Console.WriteLine("Log Level: " + loglevel);
Console.WriteLine("Log Namespace: " + logns);

Examples

This complete example shows how to get and set log properties:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            //configure connection properties
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            
            //get current log settings
            string logpath = VerticaLogProperties.LogPath;
            VerticaLogLevel loglevel = VerticaLogProperties.LogLevel;
            string logns = VerticaLogProperties.LogNamespace;
            Console.WriteLine("\nOld Log Settings:");
            Console.WriteLine("Log Path: " + logpath);
            Console.WriteLine("Log Level: " + loglevel);
            Console.WriteLine("Log Namespace: " + logns);

            //set the log path
            string path = "C:\\log";
            VerticaLogProperties.SetLogPath(path);

            // set log level
            VerticaLogLevel level = VerticaLogLevel.Debug;
            VerticaLogProperties.SetLogLevel(level);

            //set namespace to log
            string lognamespace = "Vertica";
            VerticaLogProperties.SetLogNamespace(lognamespace);
            
            //open the connection
            VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();

            //get new log settings
            logpath = VerticaLogProperties.LogPath;
            loglevel = VerticaLogProperties.LogLevel;
            logns = VerticaLogProperties.LogNamespace;
            Console.WriteLine("\nNew Log Settings:");
            Console.WriteLine("Log Path: " + logpath);
            Console.WriteLine("Log Level: " + loglevel);
            Console.WriteLine("Log Namespace: " + logns);

            //close the connection
            _conn.Close();
        }
    }
}

The example produces the following output:

Old Log Settings:
Log Path:
Log Level: None
Log Namespace:
New Log Settings:
Log Path: C:\log
Log Level: Debug
Log Namespace: Vertica

2.2 - Upgrading the client drivers

The Vertica client drivers are usually updated for each new release of the Vertica server.

The Vertica client drivers are usually updated for each new release of the Vertica server. The client driver installation packages include the version number of the corresponding Vertica server release. Usually, the drivers are forward-compatible with the next release, so your client applications are still be able to connect using the older drivers after you upgrade to the next version of Vertica Analytics Platform server. See Client driver and server version compatibility for details on which client driver versions work with each version of Vertica server.

You should upgrade your clients as soon as possible after upgrading your server to take advantage of new features and to maintain maximum compatibility with the server.

To upgrade your drivers, follow the same procedure you used to install them in the first place. The new installation will overwrite the old. See the specific instructions for installing the drivers on your client platform for any special instructions regarding upgrades.

2.3 - Setting a client connection label

A client connection label identifies a connection to the database with a user-defined string.

A client connection label identifies a connection to the database with a user-defined string. You can view the label for an existing session with GET_CLIENT_LABEL:

=> SELECT GET_CLIENT_LABEL();
      GET_CLIENT_LABEL
----------------------------
 my_client_connection_label
(1 row)

New connections

In JDBC, ODBC, and ADO.NET, you use each client driver's "Label" connection property to set the client label before connecting to the database. Setting the label before you connect ensures that the connection is associated with the label in all system and Data collector tables. Examples of these tables include SESSIONS and DC_SESSION_STARTS.

You can also preemptively set the client label with vsql by using the --label option. For details, see -g --label

Existing connections

You can set a client connection label after you connect to a Vertica database with SET_CLIENT_LABEL:

=> SELECT SET_CLIENT_LABEL('py_data_load_application');
               SET_CLIENT_LABEL
----------------------------------------------
 client_label set to py_data_load_application
(1 row)

=> SELECT GET_CLIENT_LABEL();
     GET_CLIENT_LABEL
--------------------------
 py_data_load_application
(1 row)

Certain client drivers, like JDBC, have dedicated functions for setting the client connection label for existing connections. For details, see Setting and returning a client connection label.

2.4 - Using legacy drivers

The Vertica server supports connections from previous versions of the client drivers.

The Vertica server supports connections from previous versions of the client drivers. For detailed information the compatibility between versions of the Vertica server and Vertica client, see Client driver and server version compatibility.

3 - Accessing Vertica

The following table shows which client drivers you have to set up to access Vertica with a supported programming language:.

The following table shows which client drivers you have to set up to access Vertica with a supported programming language:

Client Driver Language/Tool
JDBC Java
ODBC
  • C/C++

  • Python (pyodbc)

  • PHP

  • Perl

vertica-python Python (native client)
ADO.NET C#
vertica-nodejs JavaScript
vertica-sql-go Go

3.1 - C/C++

You must install the ODBC client driver before creating C/C++ client applications.

Vertica provides an Open Database Connectivity (ODBC) driver that allows applications to connect to the Vertica database. This driver can be used by custom-written client applications that use the ODBC API to interact with Vertica. ODBC is also used by many third-party applications to connect to Vertica, including business intelligence applications and extract, transform, and load (ETL) applications.

This section details the process for configuring the Vertica ODBC driver. It also explains how to use the ODBC API to connect to Vertica in your own client applications.

While client applications written in C, C++, Perl, PHP, etc. all use the ODBC client driver to connect to Vertica, this section only concerns C and C++ applications.

3.1.1 - ODBC architecture

The ODBC architecture has four layers:.

The ODBC architecture has four layers:

  • Client Application

    Is an application that opens a data source through a Data Source Name (DSN). It then sends requests to the data source, and receives the results of those requests. Requests are made in the form of calls to ODBC functions.

  • Driver Manager

    Is a library on the client system that acts as an intermediary between a client application and one or more drivers. The driver manager:

    • Resolves the DSN provided by the client application.

    • Loads the driver required to access the specific database defined within the DSN.

    • Processes ODBC function calls from the client or passing them to the driver.

    • Retrieves results from the driver.

    • Unloads drivers when they are no longer needed.

    On Windows and macOS client systems, the driver manager is provided by the operating system. On Linux systems, you usually need to install a driver manager. See Client drivers support for a list of driver managers that can be used with Vertica on your client platform.

  • Driver

    A library on the client system that provides access to a specific database. It translates requests into the format expected by the database, and translates results back into the format required by the client application.

  • Database

    The database processes requests initiated at the client application and returns results.

3.1.2 - ODBC feature support

The ODBC driver for Vertica supports the most of the features defined in the Microsoft ODBC 3.5 specifications.

The ODBC driver for Vertica supports the most of the features defined in the Microsoft ODBC 3.5 specifications. The following features are not supported:

  • Updatable result sets

  • Backwards scrolling cursors

  • Cursor attributes

  • More than one open statement per connection. Simultaneously executing statements must each belong to a different connection. For example, you cannot execute a new statement while another statement has a result set open. To execute another statement with the same connection/session, wait for the current statement to finish executing and close its result set, then execute the new statement.

  • Keysets

  • Bookmarks

The Vertica ODBC driver accurately reports its capabilities. If you need to determine whether it complies with a specific feature, you should query the driver's capabilities directly using the SQLGetInfo() function.

3.1.3 - Vertica and ODBC data type translation

Most data types are transparently converted between Vertica and ODBC.

Most data types are transparently converted between Vertica and ODBC. This section explains several data types require special handling.

Vertica Data Types C Data Type ODBC C Typedef C Type Identifier
BINARY, VARBINARY char[] SQL_BINARY SQL_C_BINARY
LONG VARBINARY char[] SQL_LONGVARBINARY SQL_C_BINARY
BOOLEAN SQLSMALLINT SQL_SMALLINT SQL_C_SSHORT
CHAR, VARCHAR char[] SQL_CHAR SQL_C_CHAR
LONG VARCHAR char[] SQL_LONGVARCHAR SQL_C_CHAR
DATE SQL_DATE_STRUCT SQL_TYPE_DATE SQL_C_TYPE_DATE
TIME SQL_TIME_STRUCT SQL_TYPE_TIME SQL_C_TYPE_TIME
TIMESTAMP SQL_TIMESTAMP_STRUCT SQL_TYPE_TIMESTAMP SQL_C_TYPE_TIMESTAMP
INTERVAL SQL_INTERVAL_STRUCT SQL_INTERVAL_DAY_TO_SECOND SQL_C_INTERVAL_DAY_TO_SECOND
INTERVAL DAY TO SECOND SQL_INTERVAL_STRUCT SQL_INTERVAL_DAY_TO_SECOND SQL_C_INTERVAL_DAY_TO_SECOND
INTERVAL YEAR TO MONTH SQL_INTERVAL_STRUCT SQL_INTERVAL_YEAR_TO_MONTH SQL_C_INTERVAL_YEAR_TO_MONTH
DOUBLE PRECISION FLOAT SQLREAL SQL_REAL SQL_C_FLOAT
INTEGER, BIGINT, SMALLINT SQLBIGINT SQL_BIGINT SQL_C_SBIGINT
NUMERIC, DECIMAL, NUMBER, MONEY SQL_NUMERIC_STRUCT SQL_NUMERIC SQL_C_NUMERIC
GEOMETRY char[] SQL_LONGVARBINARY SQL_C_CHAR
GEOGRAPHY char[] SQL_LONGVARBINARY SQL_C_CHAR
UUID SQLGUID (see note below) SQL_GUID SQL_C_GUID

Notes

  • The GEOMETRY and GEOGRAPHY data types are treated as LONG VARCHAR data by the ODBC driver.

  • Vertica supports the standard interval data types supported by ODBC. See Interval Data Types in Microsoft's ODBC reference.

  • Vertica version 9.0.0 introduced the UUID data type, including JDBC support for UUIDs. The Vertica ADO.NET, ODBC, and OLE DB clients added full support for UUIDs in version 9.0.1. Vertica maintains backwards compatibility with older supported client driver versions that do not support the UUID data type, as follows:

    When an older client... Vertica...
    Queries tables with UUID columns Translates the native UUID values to CHAR values.
    Inserts data into a UUID column Converts the CHAR value sent by the client into a native UUID value.
    Queries a UUID column's metadata Reports its data type as CHAR.

See also

3.1.4 - ODBC header file

The Vertica ODBC driver provides a C header file named odbc.h that defines several useful constants that you can use in your applications.

The Vertica ODBC driver provides a C header file named verticaodbc.h that defines several useful constants that you can use in your applications. These constants let you access and alter settings specific to Vertica.

This file's location depends on your client operating system:

  • /opt/vertica/include on Linux and UNIX systems.

  • C:\Program Files (x86)\Vertica\ODBC\include on Windows systems.

The constants defined in this file are listed below.

Parameter Description
SQL_ATTR_VERTICA_RESULT_BUFFER_SIZE

Sets the size of the buffer used when retrieving results from the server.

Associated functions:

SQLSetConnectAttr()
SQLGetConnectAttr()
SQL_ATTR_VERTICA_DIRECT_BATCH_INSERT

Deprecated, always set to 1.

Associated functions:

SQLSetConnectAttr()
SQLSetStmtAttr()
SQLGetConnectAttr()
SQLGetStmtAttr()
SQL_ATTR_VERTICA_LOCALE

Changes the locale from en_US@collation=binary to the ICU locale specified. See Setting the locale and encoding for ODBC sessions for an example of using this parameter.

Associated functions:

SQLSetConnectAttr()
SQLGetConnectAttr()

3.1.5 - Canceling ODBC queries

You can cancel ODBC queries with the SQLCancel() function.

You can cancel ODBC queries with the SQLCancel() function.

The following example:

  1. Creates a table odbccanceltest
  2. Queries odbccanceltest three times, canceling the third query
  3. Runs another query on dual to show that the cancelation succeeded
// Example of calling SQLCancel() during SQLFetch()
#include <stdio.h>
#include <stdlib.h>

// Only needed for Windows clients
// #include <windows.h>

// SQL data types and ODBC API functions
#include <sql.h>
#include <sqlext.h>
#include <sqltypes.h>

int main()
{
    SQLRETURN ret;   // Stores return value from ODBC API calls
    SQLHENV hdlEnv;  // Handle for the SQL environment object
    // Allocate an a SQL environment object
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
	if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate a handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated an environment handle.\n");
    }
	
    // Set the ODBC version we are going to use to 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
            (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
	if(!SQL_SUCCEEDED(ret)) {
         printf("Could not set application version to ODBC 3.\n");
         exit(EXIT_FAILURE);
    } else {
         printf("Application version set to ODBC 3.\n");
    }

    // Allocate a database handle.
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    assert(SQL_SUCCEEDED(ret));

	if(!SQL_SUCCEEDED(ret)) {
          printf("Could not allocate database handle.\n");
          exit(EXIT_FAILURE);
     } else {
          printf("Database handle allocated.\n");
     }

	// Connect to the database using
    // SQL Connect
    printf("Connecting to database.\n");
    const char *dsnName = "ExampleDB";
    const char* userID = "ExampleUser";
    const char* passwd = "password123";
    ret = SQLConnect(hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS,(SQLCHAR*)userID,SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not connect to database.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Connected to database.\n");
    }
	
    // Query the v_monitor.current_session table to find the name of the node we've connected to.

    // Set up a statement handle
    SQLHSTMT hdlStmt;
    SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);
    assert(SQL_SUCCEEDED(ret));

	// Create and populate the sampel table odbccanceltest to test SQLCancel()
	SQLExecDirect(hdlStmt, (SQLCHAR *)"CREATE TABLE odbccanceltest(id INTEGER, time TIMESTAMP)",
			  SQL_NTS);             
	SQLExecDirect(hdlStmt,
			(SQLCHAR *)"INSERT INTO odbccanceltest SELECT row_number() "
					   "OVER(), slice_time FROM(SELECT slice_time FROM( "
					   "SELECT  '2021-01-01'::timestamp s UNION ALL SELECT "
					   "'2022-01-01'::timestamp s) sq TIMESERIES "
					   "slice_time AS '1 second' OVER(ORDER BY s)) sq2;",
			SQL_NTS);
			
	ret = SQLPrepare(hdlStmt, (SQLCHAR *)"SELECT id, time FROM "
							"odbccanceltest LIMIT 5000000", SQL_NTS) ;
	
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not create prepared statement\n");
        SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
        SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
        SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
        exit(EXIT_FAILURE);
    } else {
        printf("Ceated prepared statement.\n");
    }	
	
	SQLINTEGER d;
    size_t count = 0;
    while (SQLFetch(hdlStmt) == SQL_SUCCESS) {
        ++count;
        SQLGetData(hdlStmt, 1, SQL_C_SLONG, (SQLPOINTER)&d, sizeof(d), NULL);
		// Cancel the third query
        if (count > 3) {
            SQLCancel(hdlStmt);
            break;
        }
    }
	
	// Run a follow-up query  
    ret = SQLPrepare(hdlStmt, (SQLCHAR *)"SELECT 1 FROM dual", SQL_NTS);
    ret = SQLExecute(hdlStmt)

    if (!SQL_SUCCEEDED(ret)) {
        printf("Error in SQLExecute.\n");
        exit(EXIT_FAILURE);
    }

	while (SQLFetch(hdlStmt) == SQL_SUCCESS) {
		;
	}
	
	// Free handles
    printf("Disconnecting and freeing handles.\n");
    ret = SQLDisconnect( hdlDbc );
    if(!SQL_SUCCEEDED(ret)) {
        printf("Error disconnecting from database. Transaction might still be open.\n");
        exit(EXIT_FAILURE);
    }

    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    exit(EXIT_SUCCESS);
}

3.1.6 - Connecting to the database

The first step in any ODBC application is to connect to the database.

The first step in any ODBC application is to connect to the database. When you create the connection to a data source using ODBC, you use the name of the DSN that contains the details of the driver to use, the database host, and other basic information about connecting to the data source.

There are 4 steps your application needs to take to connect to a database:

  1. Call SQLAllocHandle() to allocate a handle for the ODBC environment. This handle is used to create connection objects and to set application-wide settings.

  2. Use the environment handle to set the version of ODBC that your application wants to use. This ensures that the data source knows which API your application will use to interact with it.

  3. Allocate a database connection handle by calling SQLAllocHandle(). This handle represents a connection to a specific data source.

  4. Use the SQLConnect() or SQLDriverConnect() functions to open the connection to the database.

When creating the connection to the database, use SQLConnect() when the only options you need to set at connection time is the username and password. Use SQLDriverConnect() when you want to change connection options, such as the locale.

The following example demonstrates connecting to a database using a DSN named ExampleDB. After it creates the connection successfully, this example simply closes it.

// Demonstrate connecting to Vertica using ODBC.
// Standard i/o library
#include <stdio.h>
#include <stdlib.h>
// Only needed for Windows clients
// #include <windows.h>
// SQL include files that define data types and ODBC API
// functions
#include <sql.h>
#include <sqlext.h>
#include <sqltypes.h>
int main()
{
    SQLRETURN ret;   // Stores return value from ODBC API calls
    SQLHENV hdlEnv;  // Handle for the SQL environment object
    // Allocate an a SQL environment object
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate a handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated an environment handle.\n");
    }

    // Set the ODBC version we are going to use to
    // 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
            (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    if(!SQL_SUCCEEDED(ret)) {
         printf("Could not set application version to ODBC 3.\n");
         exit(EXIT_FAILURE);
    } else {
         printf("Set application version to ODBC 3.\n");
    }
    // Allocate a database handle.
    SQLHDBC hdlDbc;
     ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
     if(!SQL_SUCCEEDED(ret)) {
          printf("Could not allocate database handle.\n");
          exit(EXIT_FAILURE);
     } else {
          printf("Allocated Database handle.\n");
     }
    // Connect to the database using
    // SQL Connect
    printf("Connecting to database.\n");
    const char *dsnName = "ExampleDB";
    const char* userID = "ExampleUser";
    const char* passwd = "password123";
    ret = SQLConnect(hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS,(SQLCHAR*)userID,SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not connect to database.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Connected to database.\n");
    }
    // We're connected. You can do real
    // work here

    // When done, free all of the handles to close them
    // in an orderly fashion.
    printf("Disconnecting and freeing handles.\n");
    ret = SQLDisconnect( hdlDbc );
    if(!SQL_SUCCEEDED(ret)) {
        printf("Error disconnecting from database. Transaction still open?\n");
        exit(EXIT_FAILURE);
    }

    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    exit(EXIT_SUCCESS);
}

Running the above code prints the following:

Allocated an environment handle.
Set application version to ODBC 3.
Allocated Database handle.
Connecting to database.
Connected to database.
Disconnecting and freeing handles.

See Setting the locale and encoding for ODBC sessions for an example of using SQLDriverConnect to connect to the database.

Notes

  • If you use the DataDirect® driver manager, you should always use the SQL_DRIVER_NOPROMPT value for the SQLDriverConnect function's DriverCompletion parameter (the final parameter in the function call) when connecting to Vertica. Vertica's ODBC driver on Linux and UNIX platforms does not contain a UI, and therefore cannot prompt users for a password.

  • On Windows client platforms, the ODBC driver can prompt users for connection information. See Prompting windows users for missing connection properties for more information.

  • If your database does not comply with your Vertica license agreement, your application receives a warning message in the return value of the SQLConnect() function. Always have your application examine this return value to see if it is SQL_SUCCESS_WITH_INFO. If it is, have your application extract and display the message to the user.

3.1.7 - Load balancing

To enable native load balancing on your client, set the ConnectionLoadBalance connection parameter to true either in the DSN entry or in the connection string.

Native connection load balancing

Native connection load balancing helps spread the overhead caused by client connections on the hosts in the Vertica database. Both the server and the client must enable native connection load balancing. If enabled by both, then when the client initially connects to a host in the database, the host picks a host to handle the client connection from a list of the currently up hosts in the database, and informs the client which host it has chosen.

If the initially-contacted host does not choose itself to handle the connection, the client disconnects, then opens a second connection to the host selected by the first host. The connection process to this second host proceeds as usual—if SSL is enabled, then SSL negotiations begin, otherwise the client begins the authentication process. See About native connection load balancing for details.

To enable native load balancing on your client, set the ConnectionLoadBalance connection parameter to true either in the DSN entry or in the connection string. The following example demonstrates connecting to the database several times with native connection load balancing enabled, and fetching the name of the node handling the connection from the V_MONITOR.CURRENT_SESSION system table.

// Demonstrate enabling native load connection balancing.
// Standard i/o library
#include <stdlib.h>
#include <iostream>
#include <assert.h>
// Only needed for Windows clients
// #include <windows.h>
// SQL include files that define data types and ODBC API
// functions
#include <sql.h>
#include <sqlext.h>
#include <sqltypes.h>

using namespace std;
int main()
{
    SQLRETURN ret;   // Stores return value from ODBC API calls
    SQLHENV hdlEnv;  // Handle for the SQL environment object
    // Allocate an a SQL environment object
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    assert(SQL_SUCCEEDED(ret));

    // Set the ODBC version we are going to use to
    // 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
            (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    assert(SQL_SUCCEEDED(ret));

    // Allocate a database handle.
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    assert(SQL_SUCCEEDED(ret));

    // Connect four times. If load balancing is on, client should
    // connect to different nodes.
    for (int x=1; x <= 4; x++) {

        // Connect to the database using SQLDriverConnect. Set
        // ConnectionLoadBalance to 1 (true) to enable load
        // balancing.
        cout << endl << "Connection attempt #" << x << "... ";
        const char *connStr = "DSN=VMart;ConnectionLoadBalance=1;"
            "UID=ExampleUser;PWD=password123";


        ret = SQLDriverConnect(hdlDbc, NULL, (SQLCHAR*)connStr, SQL_NTS,
               NULL, 0, NULL, SQL_DRIVER_NOPROMPT );
        if(!SQL_SUCCEEDED(ret)) {
            cout << "failed. Exiting." << endl;
            exit(EXIT_FAILURE);
        } else {
            cout << "succeeded" << endl;
        }
        // We're connected. Query the v_monitor.current_session table to
        // find the name of the node we've connected to.

        // Set up a statement handle
        SQLHSTMT hdlStmt;
        SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);
        assert(SQL_SUCCEEDED(ret));

        ret = SQLExecDirect( hdlStmt, (SQLCHAR*)"SELECT node_name FROM "
            "V_MONITOR.CURRENT_SESSION;", SQL_NTS );

        if(SQL_SUCCEEDED(ret)) {
            // Bind varible to column in result set.
            SQLTCHAR node_name[256];
            ret = SQLBindCol(hdlStmt, 1, SQL_C_TCHAR, (SQLPOINTER)node_name,
                sizeof(node_name), NULL);
            while(SQL_SUCCEEDED(ret = SQLFetchScroll(hdlStmt, SQL_FETCH_NEXT,1))) {
                // Print the bound variables, which now contain the values from the
                // fetched row.
                cout << "Connected to node " << node_name << endl;
            }
        }
        // Free statement handle
        SQLFreeHandle(SQL_HANDLE_STMT,hdlStmt);
        cout << "Disconnecting." << endl;
        ret = SQLDisconnect( hdlDbc );
        assert(SQL_SUCCEEDED(ret));
    }
    // When done, free all of the handles to close them
    // in an orderly fashion.
    cout << endl << "Freeing handles..." << endl;
    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    cout << "Done!" << endl;
    exit(EXIT_SUCCESS);
}

Running the above example produces output similar to the following:

Connection attempt #1... succeeded
Connected to node v_vmart_node0001
Disconnecting.

Connection attempt #2... succeeded
Connected to node v_vmart_node0002
Disconnecting.

Connection attempt #3... succeeded
Connected to node v_vmart_node0003
Disconnecting.

Connection attempt #4... succeeded
Connected to node v_vmart_node0001
Disconnecting.

Freeing handles...
Done!

Hostname-based load balancing

You can also balance workloads by resolving a single hostname to multiple IP addresses. The ODBC client driver load balances by automatically resolving the hostname to one of the specified IP addresses at random.

For example, suppose the hostname verticahost.example.com has the following entries in etc/hosts:

192.0.2.0 verticahost.example.com
192.0.2.1 verticahost.example.com
192.0.2.2 verticahost.example.com

Specifying the hostname verticahost.example.com randomly resolves to one of the listed IP addresses.

3.1.8 - Configuring TLS for ODBC Clients

Configuring TLS for ODBC clients requires that you configure Vertica for client-server TLS and set the SSLMode connection property.

You can configure TLS for ODBC clients by setting the DSN connection properties setting the DSN connection properties for the following. For details on these parameters, see ODBC DSN connection properties:

  • SSLMode: Determines whether TLS is required and how the client should behave if the TLS connection attempt fails.
  • SSLCertFile (SSL CA file in Windows): The absolute path of the client's public certificate file.
  • SSLKeyFile (SSL cert file in Windows): The absolute path to the client's private key file.

SSLModes: Verify_ca and verify_full

You can use the SSLMode property values verify_ca and verify_full if you want the client to verify the server's information before establishing the connection. If any of these verifications fail, the connection fails:

  • verify_ca: The client verifies that the server's certificate is from a trusted certificate authority (CA).
  • verify_full: The client verifies both that the server's certificate is from a trusted CA and that the server's hostname matches the hostname on the certificate.

If verify_ca or verify_full are specified, the client requires the following to establish the connection:

  • The root.crt, which is the certificate of a CA trusted by both the server and the client.
  • The server must have:
    • server.crt, a certificate signed by the trusted CA.
    • server.key, the server's private key.
  • For verify_full, each server node must meet one of the following requirements:
    • Its hostname matches the common name specified in server.crt.
    • Its hostname or IP address appears in the Subject Alternative Name (SAN) field of server.crt.

TLS behavior flowchart

The following diagram shows an example flowchart for a client connecting with TLS.

In this example:

  • If SSLMode is set to none or allow, the client connects without authentication.
  • If SSLMode is set to verify_ca or verify_full and the client does not have root.crt, the connection fails.
  • At the SSL authentication node, if the SSLMode connection is set to verify_full and the server hostname differs from the hostname specified by the client, authentication fails.

Example ODBC TLS flow

3.1.9 - Connection failover

When run, the example's output on the system console is similar to the following:.

If a client application attempts to connect to a host in the Vertica cluster that is down, the connection attempt fails when using the default connection configuration. This failure usually returns an error to the user. The user must either wait until the host recovers and retry the connection or manually edit the connection settings to choose another host.

Due to Vertica Analytic Database's distributed architecture, you usually do not care which database host handles a client application's connection. You can use the client driver's connection failover feature to prevent the user from getting connection errors when the host specified in the connection settings is unreachable. The JDBC driver gives you several ways to let the client driver automatically attempt to connect to a different host if the one specified in the connection parameters is unreachable:

  • Configure your DNS server to return multiple IP addresses for a host name. When you use this host name in the connection settings, the client attempts to connect to the first IP address from the DNS lookup. If the host at that IP address is unreachable, the client tries to connect to the second IP, and so on until it either manages to connect to a host or it runs out of IP addresses.

  • Supply a list of backup hosts for the client driver to try if the primary host you specify in the connection parameters is unreachable.

  • (JDBC only) Use driver-specific connection properties to manage timeouts before attempting to connect to the next node.

For all methods, the process of failover is transparent to the client application (other than specifying the list of backup hosts, if you choose to use the list method of failover). If the primary host is unreachable, the client driver automatically tries to connect to other hosts.

Failover only applies to the initial establishment of the client connection. If the connection breaks, the driver does not automatically try to reconnect to another host in the database.

Choosing a failover method

You usually choose to use one of the two failover methods. However, they do work together. If your DNS server returns multiple IP addresses and you supply a list of backup hosts, the client first tries all of the IPs returned by the DNS server, then the hosts in the backup list.

The DNS method of failover centralizes the configuration client failover. As you add new nodes to your Vertica Analytic Database cluster, you can choose to add them to the failover list by editing the DNS server settings. All client systems that use the DNS server to connect to Vertica Analytic Database automatically use connection failover without having to change any settings. However, this method does require administrative access to the DNS server that all clients use to connect to the Vertica Analytic Database cluster. This may not be possible in your organization.

Using the backup server list is easier than editing the DNS server settings. However, it decentralizes the failover feature. You may need to update the application settings on each client system if you make changes to your Vertica Analytic Database cluster.

Using DNS failover

To use DNS failover, you need to change your DNS server's settings to map a single host name to multiple IP addresses of hosts in your Vertica Analytic Database cluster. You then have all client applications use this host name to connect to Vertica Analytic Database.

You can choose to have your DNS server return as many IP addresses for the host name as you want. In smaller clusters, you may choose to have it return the IP addresses of all of the hosts in your cluster. However, for larger clusters, you should consider choosing a subset of the hosts to return. Otherwise there can be a long delay as the client driver tries unsuccessfully to connect to each host in a database that is down.

Using the backup host list

To enable backup list-based connection failover, your client application has to specify at least one IP address or host name of a host in the BackupServerNode parameter. The host name or IP can optionally be followed by a colon and a port number. If not supplied, the driver defaults to the standard Vertica port number (5433). To list multiple hosts, separate them by a comma.

The following example demonstrates setting the BackupServerNode connection parameter to specify additional hosts for the connection attempt. The connection string intentionally has a non-existent node, so that the initial connection fails. The client driver has to resort to trying the backup hosts to establish a connection to Vertica.

// Demonstrate using connection failover.
// Standard i/o library
#include <stdlib.h>
#include <iostream>
#include <assert.h>

// Only needed for Windows clients
// #include <windows.hgt;

// SQL include files that define data types and ODBC API
// functions
#include <sql.h>
#include <sqlext.h>
#include <sqltypes.h>

using namespace std;

int main()
{
    SQLRETURN ret;   // Stores return value from ODBC API calls
    SQLHENV hdlEnv;  // Handle for the SQL environment object
    // Allocate an a SQL environment object
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    assert(SQL_SUCCEEDED(ret));

    // Set the ODBC version we are going to use to
    // 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
            (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    assert(SQL_SUCCEEDED(ret));

    // Allocate a database handle.
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    assert(SQL_SUCCEEDED(ret));

/* DSN for this connection specifies a bad node, and good backup nodes:
[VMartBadNode]
Description=VMart Vertica Database
Driver=/opt/vertica/lib64/libverticaodbc.so
Database=VMart
Servername=badnode.example.com
BackupServerNode=v_vmart_node0002.example.com,v_vmart_node0003.example.com
*/

    // Connect to the database using SQLConnect
    cout << "Connecting to database." << endl;
    const char *dsnName = "VMartBadNode"; // Name of the DSN
    const char* userID = "ExampleUser"; // Username
    const char* passwd = "password123"; // password
    ret = SQLConnect(hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS,(SQLCHAR*)userID,SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        cout << "Could not connect to database." << endl;
        exit(EXIT_FAILURE);
    } else {
        cout << "Connected to database." << endl;
    }
    // We're connected. Query the v_monitor.current_session table to
    // find the name of the node we've connected to.

    // Set up a statement handle
    SQLHSTMT hdlStmt;
    SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);
    assert(SQL_SUCCEEDED(ret));

    ret = SQLExecDirect( hdlStmt, (SQLCHAR*)"SELECT node_name FROM "
        "v_monitor.current_session;", SQL_NTS );

    if(SQL_SUCCEEDED(ret)) {
        // Bind varible to column in result set.
        SQLTCHAR node_name[256];
        ret = SQLBindCol(hdlStmt, 1, SQL_C_TCHAR, (SQLPOINTER)node_name,
            sizeof(node_name), NULL);
        while(SQL_SUCCEEDED(ret = SQLFetchScroll(hdlStmt, SQL_FETCH_NEXT,1))) {
            // Print the bound variables, which now contain the values from the
            // fetched row.
            cout << "Connected to node " << node_name << endl;
        }
    }

    cout << "Disconnecting." << endl;
    ret = SQLDisconnect( hdlDbc );
    assert(SQL_SUCCEEDED(ret));

    // When done, free all of the handles to close them
    // in an orderly fashion.
    cout << endl << "Freeing handles..." << endl;
    SQLFreeHandle(SQL_HANDLE_STMT,hdlStmt);
    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    cout << "Done!" << endl;
    exit(EXIT_SUCCESS);
}

When run, the example's output on the system console is similar to the following:

Connecting to database.
Connected to database.
Connected to node v_vmart_node0002
Disconnecting.

Freeing handles...
Done!

Notice that the connection was made to the first node in the backup list (node 2).

3.1.10 - Prompting windows users for missing connection properties

The Vertica Windows ODBC driver can prompt the user for connection information if required information is missing.

The Vertica Windows ODBC driver can prompt the user for connection information if required information is missing. The driver displays the Vertica Connection Dialog if the client application calls SQLDriverConnect to connect to Vertica and either of the following is true:

  • The DriverCompletion property is set to SQL_DRIVER_PROMPT.

  • The DriverCompletion property is set to SQL_DRIVER_COMPLETE or SQL_DRIVER_COMPLETE_REQUIRED and the connection string or DSN being used to connect is missing the server, database, or port information.

If either of the above conditions are true, the driver displays a Vertica Connection Dialog to the user to prompt for connection information.

The dialog has all of the property values supplied in the connection string or DSN filled in.

The required fields on the connection dialog are Database, UID, Server, and Port. Once these are filled in, the form enables the OK button.

If the user clicks Cancel on the dialog, the SQLDriverConnect function call returns SQL_NO_DATA immediately, without attempting to connect to Vertica. If the user supplies incomplete or incorrect information for the connection, the connection function returns SQL_ERROR after the connection attempt fails.

3.1.11 - Prompting windows users for passwords

If the connection string or DSN supplied to the SQLDriverConnect function that client applications call to connect to Vertica lacks any of the required connection properties needed to connect, the Vertica's Windows ODBC driver opens a dialog box to prompt the user to enter the missing information (see Prompting Windows Users for Missing Connection Parameters).

If the connection string or DSN supplied to the SQLDriverConnect function that client applications call to connect to Vertica lacks any of the required connection properties needed to connect, the Vertica's Windows ODBC driver opens a dialog box to prompt the user to enter the missing information (see Prompting windows users for missing connection properties). The user's password is not normally considered a required connection property because Vertica user accounts may not have a password. If the password property is missing, the ODBC driver still tries to connect to Vertica without supplying a password.

You can use the PromptOnNoPassword DSN parameter to force ODBC driver to treat the password as a required connection property. This parameter is useful if you do not want to store passwords in DSN entries. Passwords saved in DSN entries are insecure, since they are stored as clear text in the Windows registry and therefore visible to other users on the same system.

There are two other factors which also decide whether the ODBC driver displays the Vertica Connection Dialog. These are (in order of priority):

  • The SQLDriverConnect function call's DriverCompletion parameter.

  • Whether the DSN or connection string contain a password

The following table shows how the PromptOnNoPassword DSN parameter, the DriverCompletion parameter of the SQLDriverConnect function, and whether the DSN or connection string contains a password interact to control whether the Vertica Connection dialog appears.

PromptOnNoPassword Setting DriverCompletion Value DSN or Connection String Contains Password? Vertica Connection Dialog Displays? Notes
any value SQL_DRIVER_PROMPT any case Yes This DriverCompletion value forces the dialog to always appear, even if all required connection properties are supplied.
any value SQL_DRIVER_NOPROMPT any case No This DriverCompletion value always prevents the dialog from appearing.
any value SQL_DRIVER_COMPLETE Yes No Connection dialog displays if another required connection property is missing.
true SQL_DRIVER_COMPLETE No Yes
false (default) SQL_DRIVER_COMPLETE No No Connection dialog displays if another required connection property is missing.

The following example code demonstrates using the PromptOnNoPassword DSN parameter along with a system DSN in C++:

wstring connectString = L "DSN=VerticaDSN;PromptOnNoPassword=1;";
retcode = SQLDriverConnect(
    hdbc,
    0,
    (SQLWCHAR * ) connectString.c_str(),
    connectString.length(),
    OutConnStr,
    255, &
    amp; OutConnStrLen,
    SQL_DRIVER_COMPLETE);

No password entry vs. empty passwords

There is a difference between not having a password property in the connection string or DSN and having an empty password. The PromptOnNoPassword DSN parameter only has an effect if the connection string or DSN does not have a PWD property (which holds the user's password). If it does, even if it is empty, PromptOnNoPassword will not prompt the Windows ODBC driver to display the Vertica Connection Dialog.

This difference can cause confusion if you are using a DSN to provide the properties for your connection. Once you enter a password for a DSN connection in the Windows ODBC Manager and save it, Windows adds a PWD property to the DSN definition in the registry. If you later delete the password, the PWD property remains in the DSN definition—value is just set to an empty string. The PWD property is created even if you just use the Test button on the ODBC Manager dialog to test the DSN and later clear it before saving the DSN.

Once the password has been set, the only way to remove the PWD property from the DSN definition is to delete it using the Windows Registry Editor:

  1. On the Windows Start menu, click Run.

  2. In the Run dialog, type regedit, then click OK.

  3. In the Registry Editor window, click Edit > Find (or press Ctrl+F).

  4. In the Find window, enter the name of the DSN whose PWD property you want to delete and click OK.

  5. If find operation did not locate a folder under the ODBC.INI folder, click Edit > Find Next (or press F3) until the folder matching your DSN's name is highlighted.

  6. Select the PWD entry and press Delete.

  7. Click Yes to confirm deleting the value.

The DSN now does not have a PWD property and can trigger the connection dialog to appear when used along with PromptOnNoPassword=true and DriverConnect=SQL_DRIVER_COMPLETE.

3.1.12 - Setting the locale and encoding for ODBC sessions

Vertica provides the following methods to set the locale and encoding for an ODBC session:.

Vertica provides the following methods to set the locale and encoding for an ODBC session:

  • Specify the locale for all connections made using the DSN:

  • Set the Locale connection parameter in the connection string in SQLDriverConnect() function. For example:

    SQLDriverConnect(conn, NULL, (SQLCHAR*)"DSN=Vertica;Locale=en_GB@collation=binary", SQL_NTS, szConnOut, sizeof(szConnOut), &iAvailable, SQL_DRIVER_NOPROMPT)
    
  • Use SQLSetConnectAttr() to set the encoding and locale. In general, you should always set the encoding with this function as opposed to, for example, setting it in the DSN.

    • Pass the SQL_ATTR_VERTICA_LOCALE constant and the ICU string as the attribute value. For example:

      => SQLSetConnectAttr(hdlDbc, SQL_ATTR_VERTICA_LOCALE, (SQLCHAR*)newLocale,
              SQL_NTS);
      
    • Pass the SQL_ATTR_AP_WCHAR_TYPE constant and the encoding as the attribute value. For example:

      => rc = SQLSetConnectAttr (hdbc, SQL_ATTR_APP_WCHAR_TYPE, (void *)SQL_DD_CP_UTF16, SQL_IS_INTEGER);
      

Notes

  • Having the client system use a non-Unicode locale (such as setting LANG=C on Linux platforms) and using a Unicode locale for the connection to Vertica can result in errors such as "(10170) String data right truncation on data from data source." If data received from Vertica isn't in UTF-8 format. The driver allocates string memory based on the system's locale setting, and non-UTF-8 data can trigger an overrun. You can avoid these errors by always using a Unicode locale on the client system.

    If you specify a locale either in the connection string or in the DSN, the call to the connection function returns SQL_SUCCESS_WITH_INFO on a successful connection, with messages about the state of the locale.

  • ODBC applications can be in either ANSI or Unicode mode:

    • If Unicode, the encoding used by ODBC is UCS-2.

    • If ANSI, the data must be in single-byte ASCII, which is compatible with UTF-8 on the database server.

    The ODBC driver converts UCS-2 to UTF-8 when passing to the Vertica server and converts data sent by the Vertica server from UTF-8 to UCS-2.

  • If the end-user application is not already in UCS-2, the application is responsible for converting the input data to UCS-2, or unexpected results could occur. For example:

    • On non-UCS-2 data passed to ODBC APIs, when it is interpreted as UCS-2, it could result in an invalid UCS-2 symbol being passed to the APIs, resulting in errors.

    • Or the symbol provided in the alternate encoding could be a valid UCS-2 symbol; in this case, incorrect data is inserted into the database.

    ODBC applications should set the correct server session locale using SQLSetConnectAttr (if different from database-wide setting) in order to set the proper collation and string functions behavior on server.

The following example code demonstrates setting the locale using both the connection string and with the SQLSetConnectAttr() function.

// Standard i/o library
#include <stdio.h>
#include <stdlib.h>
// Only needed for Windows clients
// #include <windows.h>
// SQL include files that define data types and ODBC API
// functions
#include <sql.h>
#include <sqlext.h>
#include <sqltypes.h>
// Vertica-specific definitions. This include file is located as
// /opt/vertica/include on database hosts.
#include <verticaodbc.h>
int main()
{
    SQLRETURN ret;   // Stores return value from ODBC API calls
    SQLHENV hdlEnv;  // Handle for the SQL environment object
    // Allocate an a SQL environment object
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate a handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated an environment handle.\n");
    }
    // Set the ODBC version we are going to use to 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
        (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not set application version to ODBC 3.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Set application version to ODBC 3.\n");
    }
    // Allocate a database handle.
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate database handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated Database handle.\n");
    }
    // Connect to the database using SQLDriverConnect
    printf("Connecting to database.\n");
    // Set the locale to English in Great Britain.
    const char *connStr = "DSN=ExampleDB;locale=en_GB;"
        "UID=dbadmin;PWD=password123";
    ret = SQLDriverConnect(hdlDbc, NULL, (SQLCHAR*)connStr, SQL_NTS,
               NULL, 0, NULL, SQL_DRIVER_NOPROMPT );
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not connect to database.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Connected to database.\n");
    }
    // Get the Locale
    char locale[256];
    SQLGetConnectAttr(hdlDbc, SQL_ATTR_VERTICA_LOCALE, locale, sizeof(locale),
        0);
    printf("Locale is set to: %s\n", locale);
    // Set the locale to a new value
    const char* newLocale = "en_GB";
    SQLSetConnectAttr(hdlDbc, SQL_ATTR_VERTICA_LOCALE, (SQLCHAR*)newLocale,
        SQL_NTS);

    // Get the Locale again
    SQLGetConnectAttr(hdlDbc, SQL_ATTR_VERTICA_LOCALE, locale, sizeof(locale),
        0);
    printf("Locale is now set to: %s\n", locale);

    // Set the encoding
    SQLSetConnectAttr (hdbc, SQL_ATTR_APP_WCHAR_TYPE, (void *)SQL_DD_CP_UTF16,
        SQL_IS_INTEGER);

    // When done, free all of the handles to close them
    // in an orderly fashion.
    printf("Disconnecting and freeing handles.\n");
    ret = SQLDisconnect( hdlDbc );
    if(!SQL_SUCCEEDED(ret)) {
        printf("Error disconnecting from database. Transaction still open?\n");
        exit(EXIT_FAILURE);
    }
    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    exit(EXIT_SUCCESS);
}

3.1.13 - AUTOCOMMIT and ODBC transactions

The AUTOCOMMIT connection attribute controls whether INSERT, ALTER, COPY and other data-manipulation statements are automatically committed after they complete.

The AUTOCOMMIT connection attribute controls whether INSERT, ALTER, COPY and other data-manipulation statements are automatically committed after they complete. By default, AUTOCOMMIT is enabled—all statements are committed after they execute. This is often not the best setting to use, since it is less efficient. Also, you often want to control whether a set of statements are committed as a whole, rather than have each individual statement committed. For example, you may only want to commit a series of inserts if all of the inserts succeed. With AUTOCOMMIT disabled, you can roll back the transaction if one of the statements fail.

If AUTOCOMMIT is on, the results of statements are committed immediately after they are executed. You cannot roll back a statement executed in AUTOCOMMIT mode.

For example, when AUTOCOMMIT is on, the following single INSERT statement is automatically committed:

ret = SQLExecDirect(hdlStmt, (SQLCHAR*)"INSERT INTO customers VALUES(500,"
    "'Smith, Sam', '123-456-789');", SQL_NTS);

If AUTOCOMMIT is off, you need to manually commit the transaction after executing a statement. For example:

ret = SQLExecDirect(hdlStmt, (SQLCHAR*)"INSERT INTO customers VALUES(500,"
    "'Smith, Sam', '123-456-789');", SQL_NTS);
// Other inserts and data manipulations
// Commit the statements(s)
ret = SQLEndTran(SQL_HANDLE_DBC, hdlDbc, SQL_COMMIT);

The inserted row is only committed when you call SQLEndTran(). You can roll back the INSERT and other statements at any point before committing the transaction.

The following example demonstrates turning off AUTOCOMMIT, executing an insert, then manually committing the transaction.

// Some standard headers
#include <stdio.h>
#include <stdlib.h>
// Only needed for Windows clients
// #include <windows.h>
// Standard ODBC headers
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>
int main()
{
    // Set up the ODBC environment
    SQLRETURN ret;
    SQLHENV hdlEnv;
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate a handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated an environment handle.\n");
    }
    // Tell ODBC that the application uses ODBC 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
        (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not set application version to ODBC3.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Set application to ODBC 3.\n");
    }
    // Allocate a database handle.
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate database handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated Database handle.\n");
    }
    // Connect to the database
    printf("Connecting to database.\n");
    const char *dsnName = "ExampleDB";
    const char* userID = "dbadmin";
    const char* passwd = "password123";
    ret = SQLConnect(hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS,(SQLCHAR*)userID,SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not connect to database.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Connected to database.\n");
    }
    // Get the AUTOCOMMIT state
    SQLINTEGER  autoCommitState;
    SQLGetConnectAttr(hdlDbc, SQL_ATTR_AUTOCOMMIT, &autoCommitState, 0, NULL);
    printf("Autocommit is set to: %d\n", autoCommitState);


    // Disable AUTOCOMMIT
    printf("Disabling autocommit.\n");
    ret = SQLSetConnectAttr(hdlDbc, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_OFF,
        SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not disable autocommit.\n");
        exit(EXIT_FAILURE);
    }

    // Get the AUTOCOMMIT state again
    SQLGetConnectAttr(hdlDbc, SQL_ATTR_AUTOCOMMIT, &autoCommitState, 0, NULL);
    printf("Autocommit is set to: %d\n", autoCommitState);

    // Set up a statement handle
    SQLHSTMT hdlStmt;
    SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);


    // Create a table to hold the data
    SQLExecDirect(hdlStmt, (SQLCHAR*)"DROP TABLE IF EXISTS customers",
        SQL_NTS);
    SQLExecDirect(hdlStmt, (SQLCHAR*)"CREATE TABLE customers "
        "(CustID int, CustName varchar(100), Phone_Number char(15));",
        SQL_NTS);


    // Insert a single row.
    ret = SQLExecDirect(hdlStmt, (SQLCHAR*)"INSERT INTO customers VALUES(500,"
        "'Smith, Sam', '123-456-789');", SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not perform single insert.\n");
    } else {
        printf("Performed single insert.\n");
    }


    // Need to commit the transaction before closing, since autocommit is
    // disabled. Otherwise SQLDisconnect returns an error.
    printf("Committing transaction.\n");
    ret =  SQLEndTran(SQL_HANDLE_DBC, hdlDbc, SQL_COMMIT);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Error committing transaction.\n");
        exit(EXIT_FAILURE);
    }

    // Clean up
    printf("Free handles.\n");
    ret = SQLDisconnect(hdlDbc);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Error disconnecting from database. Transaction still open?\n");
        exit(EXIT_FAILURE);
    }
    SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    exit(EXIT_SUCCESS);
}

Running the above code results in the following output:

Allocated an environment handle.
Set application to ODBC 3.
Allocated Database handle.
Connecting to database.
Connected to database.
Autocommit is set to: 1
Disabling autocommit.
Autocommit is set to: 0
Performed single insert.
Committing transaction.
Free handles.

3.1.14 - Retrieving data

To retrieve data through ODBC, you execute a query that returns a result set (SELECT, for example), then retrieve the results using one of two methods:.

To retrieve data through ODBC, you execute a query that returns a result set (SELECT, for example), then retrieve the results using one of two methods:

  • Use the SQLFetch() function to retrieve a row of the result set, then access column values in the row by calling SQLGetData().

  • Use the SQLBindColumn() function to bind a variable or array to a column in the result set, then call SQLExtendedFetch() or SQLFetchScroll() to read a row of the result set and insert its values into the variable or array.

In both methods you loop through the result set until you either reach the end (signaled by the SQL_NO_DATA return status) or encounter an error.

The following code example demonstrates retrieving data from Vertica by:

  1. Connecting to the database.

  2. Executing a SELECT statement that returns the IDs and names of all tables.

  3. Binds two variables to the two columns in the result set.

  4. Loops through the result set, printing the ids and name values.

// Demonstrate running a query and getting results by querying the tables
// system table for a list of all tables in the current schema.
// Some standard headers
#include <stdlib.h>
#include <sstream>
#include <iostream>
#include <assert.h>
// Standard ODBC headers
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>

// Use std namespace to make output easier
using namespace std;
// Helper function to print SQL error messages.
template <typename HandleT>
void reportError(int handleTypeEnum, HandleT hdl)
{
    // Get the status records.
    SQLSMALLINT   i, MsgLen;
    SQLRETURN ret2;
    SQLCHAR       SqlState[6], Msg[SQL_MAX_MESSAGE_LENGTH];
    SQLINTEGER    NativeError;
    i = 1;
    cout << endl;
    while ((ret2 = SQLGetDiagRec(handleTypeEnum, hdl, i, SqlState, &NativeError,
        Msg, sizeof(Msg), &MsgLen)) != SQL_NO_DATA) {
        cout << "error record #" << i++ << endl;
        cout << "sqlstate: " << SqlState << endl;
        cout << "detailed msg: " << Msg << endl;
        cout << "native error code: " << NativeError << endl;
    }
}

typedef struct {
    SQLHENV hdlEnv;
    SQLHDBC hdlDbc;
} DBConnection;

void connect(DBConnection *pConnInfo)
{
    // Set up the ODBC environment
    SQLRETURN ret;
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &pConnInfo->hdlEnv);
    assert(SQL_SUCCEEDED(ret));
    // Tell ODBC that the application uses ODBC 3.
    ret = SQLSetEnvAttr(pConnInfo->hdlEnv, SQL_ATTR_ODBC_VERSION,
        (SQLPOINTER)SQL_OV_ODBC3, SQL_IS_UINTEGER);
    assert(SQL_SUCCEEDED(ret));

    // Allocate a database handle.
    ret = SQLAllocHandle(SQL_HANDLE_DBC, pConnInfo->hdlEnv, &pConnInfo->hdlDbc);
    assert(SQL_SUCCEEDED(ret));
    // Connect to the database
    cout << "Connecting to database." << endl;
    const char* dsnName = "ExampleDB";
    const char* userID = "dbadmin";
    const char* passwd = "password123";
    ret = SQLConnect(pConnInfo->hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS, (SQLCHAR*)userID, SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if (!SQL_SUCCEEDED(ret)) {
        cout << "Could not connect to database" << endl;
        reportError<SQLHDBC>(SQL_HANDLE_DBC, pConnInfo->hdlDbc);
        exit(EXIT_FAILURE);
    }
    else {
        cout << "Connected to database." << endl;
    }
}

void disconnect(DBConnection *pConnInfo)
{
    SQLRETURN ret;
    // Clean up by shutting down the connection
    cout << "Free handles." << endl;
    ret = SQLDisconnect(pConnInfo->hdlDbc);
    if (!SQL_SUCCEEDED(ret)) {
        cout << "Error disconnecting. Transaction still open?" << endl;
        exit(EXIT_FAILURE);
    }
    SQLFreeHandle(SQL_HANDLE_DBC, pConnInfo->hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, pConnInfo->hdlEnv);
}

void executeQuery(SQLHDBC hdlDbc, SQLCHAR* pQuery)
{
    SQLRETURN ret;
    // Set up a statement handle
    SQLHSTMT hdlStmt;
    SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);
    assert(SQL_SUCCEEDED(ret));

    // Execute a query to get the names and IDs of all tables in the schema
    // search p[ath (usually public).
    ret = SQLExecDirect(hdlStmt, pQuery, SQL_NTS);

    if (!SQL_SUCCEEDED(ret)) {
        // Report error an go no further if statement failed.
        cout << "Error executing statement." << endl;
        reportError<SQLHDBC>(SQL_HANDLE_STMT, hdlStmt);
        exit(EXIT_FAILURE);
    }
    else {
        // Query succeeded, so bind two variables to the two colums in the
        // result set,
        cout << "Fetching results..." << endl;
        SQLBIGINT table_id;       // Holds the ID of the table.
        SQLTCHAR table_name[256]; // buffer to hold name of table
        ret = SQLBindCol(hdlStmt, 1, SQL_C_SBIGINT, (SQLPOINTER)&table_id,
            sizeof(table_id), NULL);
        ret = SQLBindCol(hdlStmt, 2, SQL_C_TCHAR, (SQLPOINTER)table_name,
            sizeof(table_name), NULL);

        // Loop through the results,
        while (SQL_SUCCEEDED(ret = SQLFetchScroll(hdlStmt, SQL_FETCH_NEXT, 1))) {
            // Print the bound variables, which now contain the values from the
            // fetched row.
            cout << table_id << " | " << table_name << endl;
        }


        // See if loop exited for reasons other than running out of data
        if (ret != SQL_NO_DATA) {
            // Exited for a reason other than no more data... report the error.
            reportError<SQLHDBC>(SQL_HANDLE_STMT, hdlStmt);
        }
    }
    SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
}

int main()
{
    DBConnection conn;

    connect(&conn);
    executeQuery(conn.hdlDbc,
        (SQLCHAR*)"SELECT table_id, table_name FROM tables ORDER BY table_name");
    executeQuery(conn.hdlDbc,
        (SQLCHAR*)"SELECT table_id, table_name FROM tables ORDER BY table_id");
    disconnect(&conn);
    exit(EXIT_SUCCESS);
}

Running the example code in the vmart database produces output similar to this:

Connecting to database.
Connected to database.
Fetching results...
45035996273970908 | call_center_dimension
45035996273970836 | customer_dimension
45035996273972958 | customers
45035996273970848 | date_dimension
45035996273970856 | employee_dimension
45035996273970868 | inventory_fact
45035996273970904 | online_page_dimension
45035996273970912 | online_sales_fact
45035996273970840 | product_dimension
45035996273970844 | promotion_dimension
45035996273970860 | shipping_dimension
45035996273970876 | store_dimension
45035996273970894 | store_orders_fact
45035996273970880 | store_sales_fact
45035996273972806 | t
45035996273970852 | vendor_dimension
45035996273970864 | warehouse_dimension
Fetching results...
45035996273970836 | customer_dimension
45035996273970840 | product_dimension
45035996273970844 | promotion_dimension
45035996273970848 | date_dimension
45035996273970852 | vendor_dimension
45035996273970856 | employee_dimension
45035996273970860 | shipping_dimension
45035996273970864 | warehouse_dimension
45035996273970868 | inventory_fact
45035996273970876 | store_dimension
45035996273970880 | store_sales_fact
45035996273970894 | store_orders_fact
45035996273970904 | online_page_dimension
45035996273970908 | call_center_dimension
45035996273970912 | online_sales_fact
45035996273972806 | t
45035996273972958 | customers
Free handles.

3.1.15 - Loading data

A primary task for many client applications is loading data into the Vertica database.

A primary task for many client applications is loading data into the Vertica database. There are several different ways to insert data using ODBC, which are covered by the topics in this section.

3.1.15.1 - Using a single row insert

The easiest way to load data into Vertica is to run an INSERT SQL statement using the SQLExecuteDirect function.

The easiest way to load data into Vertica is to run an INSERT SQL statement using the SQLExecuteDirect function. However this method is limited to inserting a single row of data.

ret = SQLExecDirect(hstmt, (SQLTCHAR*)"INSERT into Customers values"
      "(1,'abcda','efgh','1')", SQL_NTS);

3.1.15.2 - Using prepared statements

Vertica supports using server-side prepared statements with both ODBC and JDBC.

Vertica supports using server-side prepared statements with both ODBC and JDBC. Prepared statements let you define a statement once, and then run it many times with different parameters. The statement you want to execute contains placeholders instead of parameters. When you execute the statement, you supply values for each placeholder.

Placeholders are represented by question marks (?) as in the following example query:

SELECT * FROM public.inventory_fact WHERE product_key = ?

Server-side prepared statements are useful for:

  • Optimizing queries. Vertica only needs to parse the statement once.

  • Preventing SQL injection attacks. A SQL injection attack occurs when user input is either incorrectly filtered for string literal escape characters embedded in SQL statements or user input is not strongly typed and thereby unexpectedly run. Since a prepared statement is parsed separately from the input data, there is no chance the data can be accidentally executed by the database.

  • Binding direct variables to return columns. By pointing to data structures, the code doesn't have to perform extra transformations.

The following example demonstrates a using a prepared statement for a single insert.

// Some standard headers
#include <stdio.h>
#include <stdlib.h>
// Only needed for Windows clients
// #include <windows.h>
// Standard ODBC headers
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>
// Some constants for the size of the data to be inserted.
#define CUST_NAME_LEN 50
#define PHONE_NUM_LEN 15
#define NUM_ENTRIES 4
int main()
{
    // Set up the ODBC environment
    SQLRETURN ret;
    SQLHENV hdlEnv;
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate a handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated an environment handle.\n");
    }
    // Tell ODBC that the application uses ODBC 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
        (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not set application version to ODBC3.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Set application to ODBC 3.\n");
    }
    // Allocate a database handle.
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    // Connect to the database
    printf("Connecting to database.\n");
    const char *dsnName = "ExampleDB";
    const char* userID = "dbadmin";
    const char* passwd = "password123";
    ret = SQLConnect(hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS,(SQLCHAR*)userID,SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not connect to database.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Connected to database.\n");
    }

    // Disable AUTOCOMMIT
    printf("Disabling autocommit.\n");
    ret = SQLSetConnectAttr(hdlDbc, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_OFF,
        SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not disable autocommit.\n");
        exit(EXIT_FAILURE);
    }


    // Set up a statement handle
    SQLHSTMT hdlStmt;
    SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);
    SQLExecDirect(hdlStmt, (SQLCHAR*)"DROP TABLE IF EXISTS customers",
        SQL_NTS);
    SQLExecDirect(hdlStmt, (SQLCHAR*)"CREATE TABLE customers "
        "(CustID int, CustName varchar(100), Phone_Number char(15));",
        SQL_NTS);

    // Set up a bunch of variables to be bound to the statement
    // parameters.

    // Create the prepared statement. This will insert data into the
    // table we created above.
    printf("Creating prepared statement\n");
    ret = SQLPrepare (hdlStmt, (SQLTCHAR*)"INSERT INTO customers (CustID, "
        "CustName,  Phone_Number) VALUES(?,?,?)", SQL_NTS) ;
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not create prepared statement\n");
        SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
        SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
        SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
        exit(EXIT_FAILURE);
    } else {
        printf("Created prepared statement.\n");
    }
    SQLINTEGER custID = 1234;
    SQLCHAR custName[100] = "Fein, Fredrick";
    SQLVARCHAR phoneNum[15] = "555-123-6789";
    SQLLEN strFieldLen = SQL_NTS;
    SQLLEN custIDLen = 0;
    // Bind the data arrays to the parameters in the prepared SQL
    // statement
    ret = SQLBindParameter(hdlStmt, 1, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER,
        0, 0, &custID, 0 , &custIDLen);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not bind custID array\n");
        SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
        SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
        SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
        exit(EXIT_FAILURE);
    } else {
        printf("Bound custID to prepared statement\n");
    }
    // Bind CustNames
    SQLBindParameter(hdlStmt, 2, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_VARCHAR,
        50, 0, (SQLPOINTER)custName,  0, &strFieldLen);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not bind custNames\n");
        SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
        SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
        SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
        exit(EXIT_FAILURE);
    } else {
        printf("Bound custName to prepared statement\n");
    }
    // Bind phoneNums
    SQLBindParameter(hdlStmt, 3, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR,
        15, 0, (SQLPOINTER)phoneNum, 0, &strFieldLen);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not bind phoneNums\n");
        SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
        SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
        SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
        exit(EXIT_FAILURE);
    } else {
        printf("Bound phoneNum to prepared statement\n");
    }
    // Execute the prepared statement.
    printf("Running prepared statement...");
    ret = SQLExecute(hdlStmt);
    if(!SQL_SUCCEEDED(ret)) {
        printf("not successful!\n");
    }  else {
        printf("successful.\n");
    }

    // Done with batches, commit the transaction
    printf("Committing transaction\n");
    ret = SQLEndTran(SQL_HANDLE_DBC, hdlDbc, SQL_COMMIT);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not commit transaction\n");
    }  else {
        printf("Committed transaction\n");
    }

    // Clean up
    printf("Free handles.\n");
    ret = SQLDisconnect( hdlDbc );
    if(!SQL_SUCCEEDED(ret)) {
        printf("Error disconnecting. Transaction still open?\n");
        exit(EXIT_FAILURE);
    }
    SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    exit(EXIT_SUCCESS);
}

3.1.15.3 - Using batch inserts

You use batch inserts to insert chunks of data into the database.

You use batch inserts to insert chunks of data into the database. By breaking the data into batches, you can monitor the progress of the load by receiving information about any rejected rows after each batch is loaded. To perform a batch load through ODBC, you typically use a prepared statement with the parameters bound to arrays that contain the data to be loaded. For each batch, you load a new set of data into the arrays then execute the prepared statement.

When you perform a batch load, Vertica uses a COPY statement to load the data. Each additional batch you load uses the same COPY statement. The statement remains open until you end the transaction, close the cursor for the statement, or execute a non-INSERT statement.

Using a single COPY statement for multiple batches improves batch loading efficiency by:

  • reducing the overhead of inserting individual batches

  • combining individual batches into larger ROS containers

Even though Vertica uses a single COPY statement to insert multiple batches within a transaction, you can locate which (if any) rows were rejected due to invalid row formats or data type issues after each batch is loaded. See Tracking load status (ODBC) for details.

Since the batch loads share a COPY statement, errors in one batch can cause earlier batches in the same transaction to be rolled back.

Batch insert steps

The steps your application needs to take in order to perform an ODBC Batch Insert are:

  1. Connect to the database.

  2. Disable autocommit for the connection.

  3. Create a prepared statement that inserts the data you want to load.

  4. Bind the parameters of the prepared statement to arrays that will contain the data you want to load.

  5. Populate the arrays with the data for your batches.

  6. Execute the prepared statement.

  7. Optionally, check the results of the batch load to find rejected rows.

  8. Repeat the previous three steps until all of the data you want to load is loaded.

  9. Commit the transaction.

  10. Optionally, check the results of the entire batch transaction.

The following example code demonstrates a simplified version of the above steps.

// Some standard headers
#include <stdio.h>
#include <stdlib.h>
// Only needed for Windows clients
// #include <windows.h>
// Standard ODBC headers
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>
int main()
{
    // Number of data rows to insert
    const int NUM_ENTRIES = 4;

    // Set up the ODBC environment
    SQLRETURN ret;
    SQLHENV hdlEnv;
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate a handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated an environment handle.\n");
    }
    // Tell ODBC that the application uses ODBC 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
        (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not set application version to ODBC3.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Set application to ODBC 3.\n");
    }
    // Allocate a database handle.
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate database handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated Database handle.\n");
    }
    // Connect to the database
    printf("Connecting to database.\n");
    const char *dsnName = "ExampleDB";
    const char* userID = "dbadmin";
    const char* passwd = "password123";
    ret = SQLConnect(hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS,(SQLCHAR*)userID,SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not connect to database.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Connected to database.\n");
    }


    // Disable AUTOCOMMIT
    printf("Disabling autocommit.\n");
    ret = SQLSetConnectAttr(hdlDbc, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_OFF,
                            SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not disable autocommit.\n");
        exit(EXIT_FAILURE);
    }

    // Set up a statement handle
    SQLHSTMT hdlStmt;
    SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);

    // Create a table to hold the data
    SQLExecDirect(hdlStmt, (SQLCHAR*)"DROP TABLE IF EXISTS customers",
        SQL_NTS);
    SQLExecDirect(hdlStmt, (SQLCHAR*)"CREATE TABLE customers "
        "(CustID int, CustName varchar(100), Phone_Number char(15));",
        SQL_NTS);

    // Create the prepared statement. This will insert data into the
    // table we created above.
    printf("Creating prepared statement\n");
    ret = SQLPrepare (hdlStmt, (SQLTCHAR*)"INSERT INTO customers (CustID, "
        "CustName,  Phone_Number) VALUES(?,?,?)", SQL_NTS) ;
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not create prepared statement\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Created prepared statement.\n");
    }
    // This is the data to be inserted into the database.
    SQLCHAR custNames[][50] = { "Allen, Anna", "Brown, Bill", "Chu, Cindy",
        "Dodd, Don" };
    SQLINTEGER custIDs[] = { 100, 101, 102, 103};
    // year, month, day, hour, minute, second, fraction
    // struct accepts fraction in billionths of a second, but Vertica supports millionths
    SQL_TIMESTAMP_STRUCT accountCreationDates[] = { 
        {1997, 4, 1, 12, 35, 29, 0},          // 1997-04-01 12:35:29
        {2002, 6, 13, 1,  0, 12, 1000},       // 2002-06-13 01:00:12.000001
        {2000, 9, 2, 2,  59, 37, 999000000},  // 2000-09-02 02:59:37.999
        {2009, 1, 25, 3,  7, 59, 999999000},  // 2009-01-25 03:07:59.999999
    };
    SQLCHAR phoneNums[][15] = {"1-617-555-1234", "1-781-555-1212",
        "1-508-555-4321", "1-617-555-4444"};
    // Bind the data arrays to the parameters in the prepared SQL
    // statement. First is the custID.
    ret = SQLBindParameter(hdlStmt, 1, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER,
        0, 0, (SQLPOINTER)custIDs, sizeof(SQLINTEGER) , NULL);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not bind custID array\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Bound CustIDs array to prepared statement\n");
    }
    // Bind the customer account creation date
    // timestamp column size is safe at 23 + length of longest fractional component precision
    // Max precision that vertica supports for timestamp second precision is 6 digits
    ret = SQLBindParameter(stmt.hstmt, 2, SQL_PARAM_INPUT, SQL_C_TYPE_TIMESTAMP, SQL_TIMESTAMP, 29, 6,
                          (SQLPOINTER)accountCreationDates, sizeof(SQL_TIMESTAMP_STRUCT), NULL);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not bind account creation dates\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Bound account creation date array to prepared statement\n");
    }
    // Bind CustNames
    ret = SQLBindParameter(hdlStmt, 3, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_VARCHAR,
        50, 0, (SQLPOINTER)custNames, 50, NULL);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not bind custNames\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Bound CustNames array to prepared statement\n");
    }
    // Bind phoneNums
    ret = SQLBindParameter(hdlStmt, 4, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR,
        15, 0, (SQLPOINTER)phoneNums, 15, NULL);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not bind phoneNums\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Bound phoneNums array to prepared statement\n");
    }
    // Tell the ODBC driver how many rows we have in the
    // array.
    ret = SQLSetStmtAttr( hdlStmt, SQL_ATTR_PARAMSET_SIZE,
        (SQLPOINTER)NUM_ENTRIES, 0 );
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not bind set parameter size\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Bound phoneNums array to prepared statement\n");
    }

    // Add multiple batches to the database. This just adds the same
    // batch of data four times for simplicity's sake. Each call adds
    // the 4 rows into the database.
    for (int batchLoop=1; batchLoop<=5; batchLoop++) {
        // Execute the prepared statement, loading all of the data
        // in the arrays.
        printf("Adding Batch #%d...", batchLoop);
        ret = SQLExecute(hdlStmt);
        if(!SQL_SUCCEEDED(ret)) {
           printf("not successful!\n");
        }  else {
            printf("successful.\n");
        }
    }
    // Done with batches, commit the transaction
    printf("Committing transaction\n");
    ret = SQLEndTran(SQL_HANDLE_DBC, hdlDbc, SQL_COMMIT);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not commit transaction\n");
    }  else {
        printf("Committed transaction\n");
    }

    // Clean up
    printf("Free handles.\n");
    ret = SQLDisconnect( hdlDbc );
    if(!SQL_SUCCEEDED(ret)) {
        printf("Error disconnecting. Transaction still open?\n");
        exit(EXIT_FAILURE);
    }
    SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    exit(EXIT_SUCCESS);
}

The result of running the above code is shown below.

Allocated an environment handle.
Set application to ODBC 3.
Allocated Database handle.
Connecting to database.
Connected to database.
Creating prepared statement
Created prepared statement.
Bound CustIDs array to prepared statement
Bound CustNames array to prepared statement
Bound phoneNums array to prepared statement
Adding Batch #1...successful.
Adding Batch #2...successful.
Adding Batch #3...successful.
Adding Batch #4...successful.
Adding Batch #5...successful.
Committing transaction
Committed transaction
Free handles.

The resulting table looks like this:

=> SELECT * FROM customers;
 CustID |  CustName   |  Phone_Number
--------+-------------+-----------------
    100 | Allen, Anna | 1-617-555-1234
    101 | Brown, Bill | 1-781-555-1212
    102 | Chu, Cindy  | 1-508-555-4321
    103 | Dodd, Don   | 1-617-555-4444
    100 | Allen, Anna | 1-617-555-1234
    101 | Brown, Bill | 1-781-555-1212
    102 | Chu, Cindy  | 1-508-555-4321
    103 | Dodd, Don   | 1-617-555-4444
    100 | Allen, Anna | 1-617-555-1234
    101 | Brown, Bill | 1-781-555-1212
    102 | Chu, Cindy  | 1-508-555-4321
    103 | Dodd, Don   | 1-617-555-4444
    100 | Allen, Anna | 1-617-555-1234
    101 | Brown, Bill | 1-781-555-1212
    102 | Chu, Cindy  | 1-508-555-4321
    103 | Dodd, Don   | 1-617-555-4444
    100 | Allen, Anna | 1-617-555-1234
    101 | Brown, Bill | 1-781-555-1212
    102 | Chu, Cindy  | 1-508-555-4321
    103 | Dodd, Don   | 1-617-555-4444
(20 rows)

3.1.15.3.1 - Tracking load status (ODBC)

After loading a batch of data, your client application can get the number of rows that were processed and find out whether each row was accepted or rejected.

After loading a batch of data, your client application can get the number of rows that were processed and find out whether each row was accepted or rejected.

Finding the number of accepted rows

To get the number of rows processed by a batch, you add an attribute named SQL_ATTR_PARAMS_PROCESSED_PTR to the statement object that points to a variable to receive the number rows:

    SQLULEN rowsProcessed;
    SQLSetStmtAttr(hdlStmt, SQL_ATTR_PARAMS_PROCESSED_PTR, &rowsProcessed, 0);

When your application calls SQLExecute() to insert the batch, the Vertica ODBC driver saves the number of rows that it processed (which is not necessarily the number of rows that were successfully inserted) in the variable you specified in the SQL_ATTR_PARAMS_PROCESSED_PTR statement attribute.

Finding the accepted and rejected rows

Your application can also set a statement attribute named SQL_ATTR_PARAM_STATUS_PTR that points to an array where the ODBC driver can store the result of inserting each row:

    SQLUSMALLINT   rowResults[ NUM_ENTRIES ];
    SQLSetStmtAttr(hdlStmt, SQL_ATTR_PARAM_STATUS_PTR, rowResults, 0);

This array must be at least as large as the number of rows being inserted in each batch.

When your application calls SQLExecute to insert a batch, the ODBC driver populates the array with values indicating whether each row was successfully inserted (SQL_PARAM_SUCCESS or SQL_PARAM_SUCCESS_WITH_INFO) or encountered an error (SQL_PARAM_ERROR).

The following example expands on the example shown in Using batch inserts to include reporting the number of rows processed and the status of each row inserted.

In this example, SQLGetDiagRec() is called several times to retrieve the failures for each bulk load. SQLGetDiagRec() returns up to 50 failures for any given operation:

// Some standard headers
#include <stdio.h>
#include <stdlib.h>
// Only needed for Windows clients
// #include <windows.h>
// Standard ODBC headers
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>
// Helper function to print SQL error messages.
template <typename HandleT>
void reportError(int handleTypeEnum, HandleT hdl)
{
    // Get the status records.
    SQLSMALLINT   i, MsgLen;
    SQLRETURN ret2;
    SQLCHAR       SqlState[6], Msg[SQL_MAX_MESSAGE_LENGTH];
    SQLINTEGER    NativeError;
    i = 1;
    printf("\n");
    while ((ret2 = SQLGetDiagRec(handleTypeEnum, hdl, i, SqlState, &NativeError,
        Msg, sizeof(Msg), &MsgLen)) != SQL_NO_DATA) {
            printf("error record %d\n", i);
            printf("sqlstate: %s\n", SqlState);
            printf("detailed msg: %s\n", Msg);
            printf("native error code: %d\n\n", NativeError);
            i++;
    }
}
int main()
{
    // Number of data rows to insert
    const int NUM_ENTRIES = 4;


    SQLRETURN ret;
    SQLHENV hdlEnv;
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate a handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated an environment handle.\n");
    }
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
        (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not set application version to ODBC3.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Set application to ODBC 3.\n");
    }
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate database handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated Database handle.\n");
    }
    // Connect to the database
    printf("Connecting to database.\n");
    const char *dsnName = "ExampleDB";
    const char* userID = "dbadmin";
    const char* passwd = "password123";
    ret = SQLConnect(hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS,(SQLCHAR*)userID,SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not connect to database.\n");
        reportError<SQLHDBC>(SQL_HANDLE_DBC, hdlDbc);
        exit(EXIT_FAILURE);
    } else {
        printf("Connected to database.\n");
    }
    // Set up a statement handle
    SQLHSTMT hdlStmt;
    SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);
    SQLExecDirect(hdlStmt, (SQLCHAR*)"DROP TABLE IF EXISTS customers",
        SQL_NTS);
    // Create a table into which we can store data
    printf("Creating table.\n");
    ret = SQLExecDirect(hdlStmt, (SQLCHAR*)"CREATE TABLE customers "
        "(CustID int, CustName varchar(50), Phone_Number char(15));",
        SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        reportError<SQLHDBC>( SQL_HANDLE_STMT, hdlStmt );
        exit(EXIT_FAILURE);
    } else {
        printf("Created table.\n");
    }
    // Create the prepared statement. This will insert data into the
    // table we created above.
    printf("Creating prepared statement\n");
    ret = SQLPrepare (hdlStmt, (SQLTCHAR*)"INSERT INTO customers (CustID, "
        "CustName,  Phone_Number) VALUES(?,?,?)", SQL_NTS) ;
    if(!SQL_SUCCEEDED(ret)) {
        reportError<SQLHDBC>( SQL_HANDLE_STMT, hdlStmt );
        exit(EXIT_FAILURE);
    } else {
        printf("Created prepared statement.\n");
    }
    // This is the data to be inserted into the database.
    char custNames[][50] = { "Allen, Anna", "Brown, Bill", "Chu, Cindy",
        "Dodd, Don" };
    SQLINTEGER custIDs[] = { 100, 101, 102, 103};
    char phoneNums[][15] = {"1-617-555-1234", "1-781-555-1212",
        "1-508-555-4321", "1-617-555-4444"};
    // Bind the data arrays to the parameters in the prepared SQL
    // statement
    ret = SQLBindParameter(hdlStmt, 1, SQL_PARAM_INPUT, SQL_C_LONG, SQL_INTEGER,
        0, 0, (SQLPOINTER)custIDs, sizeof(SQLINTEGER) , NULL);
    if(!SQL_SUCCEEDED(ret)) {
        reportError<SQLHDBC>( SQL_HANDLE_STMT, hdlStmt );
        exit(EXIT_FAILURE);
    } else {
        printf("Bound CustIDs array to prepared statement\n");
    }
    // Bind CustNames
    SQLBindParameter(hdlStmt, 2, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_VARCHAR,
        50, 0, (SQLPOINTER)custNames, 50, NULL);
    if(!SQL_SUCCEEDED(ret)) {
        reportError<SQLHDBC>( SQL_HANDLE_STMT, hdlStmt );
        exit(EXIT_FAILURE);
    } else {
        printf("Bound CustNames array to prepared statement\n");
    }
    // Bind phoneNums
    SQLBindParameter(hdlStmt, 3, SQL_PARAM_INPUT, SQL_C_CHAR, SQL_CHAR,
        15, 0, (SQLPOINTER)phoneNums, 15, NULL);
    if(!SQL_SUCCEEDED(ret)) {
        reportError<SQLHDBC>( SQL_HANDLE_STMT, hdlStmt );
        exit(EXIT_FAILURE);
    } else {
        printf("Bound phoneNums array to prepared statement\n");
    }
    // Set up a variable to recieve number of parameters processed.
    SQLULEN rowsProcessed;
    // Set a statement attribute to point to the variable
    SQLSetStmtAttr(hdlStmt, SQL_ATTR_PARAMS_PROCESSED_PTR, &rowsProcessed, 0);
    // Set up an array to hold the result of each row insert
    SQLUSMALLINT   rowResults[ NUM_ENTRIES ];
    // Set a statement attribute to point to the array
    SQLSetStmtAttr(hdlStmt, SQL_ATTR_PARAM_STATUS_PTR, rowResults, 0);
    // Tell the ODBC driver how many rows we have in the
    // array.
    SQLSetStmtAttr(hdlStmt, SQL_ATTR_PARAMSET_SIZE, (SQLPOINTER)NUM_ENTRIES, 0);
    // Add multiple batches to the database. This just adds the same
    // batch of data over and over again for simplicity's sake.
    for (int batchLoop=1; batchLoop<=5; batchLoop++) {
        // Execute the prepared statement, loading all of the data
        // in the arrays.
        printf("Adding Batch #%d...", batchLoop);
        ret = SQLExecute(hdlStmt);
        if(!SQL_SUCCEEDED(ret)) {
            reportError<SQLHDBC>( SQL_HANDLE_STMT, hdlStmt );
            exit(EXIT_FAILURE);
        }
        // Number of rows processed is in rowsProcessed
        printf("Params processed: %d\n", rowsProcessed);
        printf("Results of inserting each row:\n");
        int i;
        for (i = 0; i<NUM_ENTRIES; i++) {
            SQLUSMALLINT result = rowResults[i];
            switch(rowResults[i]) {
                case SQL_PARAM_SUCCESS:
                case SQL_PARAM_SUCCESS_WITH_INFO:
                    printf("  Row %d inserted successsfully\n", i+1);
                    break;
                case SQL_PARAM_ERROR:
                    printf("  Row %d was not inserted due to an error.", i+1);
                    break;
                default:
                    printf("  Row %d had some issue with it: %d\n", i+1, result);
            }
        }
    }
    // Done with batches, commit the transaction
    printf("Commit Transaction\n");
    ret = SQLEndTran(SQL_HANDLE_DBC, hdlDbc, SQL_COMMIT);
    if(!SQL_SUCCEEDED(ret)) {
        reportError<SQLHDBC>( SQL_HANDLE_STMT, hdlStmt );
    }


    // Clean up
    printf("Free handles.\n");
    ret = SQLDisconnect( hdlDbc );
    if(!SQL_SUCCEEDED(ret)) {
        printf("Error disconnecting. Transaction still open?\n");
        exit(EXIT_FAILURE);
    }
    SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    exit(EXIT_SUCCESS);
}

Running the example code produces the following output:

Allocated an environment handle.Set application to ODBC 3.
Allocated Database handle.
Connecting to database.
Connected to database.
Creating table.
Created table.
Creating prepared statement
Created prepared statement.
Bound CustIDs array to prepared statement
Bound CustNames array to prepared statement
Bound phoneNums array to prepared statement
Adding Batch #1...Params processed: 4
Results of inserting each row:
  Row 1 inserted successfully
  Row 2 inserted successfully
  Row 3 inserted successfully
  Row 4 inserted successfully
Adding Batch #2...Params processed: 4
Results of inserting each row:
  Row 1 inserted successfully
  Row 2 inserted successfully
  Row 3 inserted successfully
  Row 4 inserted successfully
Adding Batch #3...Params processed: 4
Results of inserting each row:
  Row 1 inserted successfully
  Row 2 inserted successfully
  Row 3 inserted successfully
  Row 4 inserted successfully
Adding Batch #4...Params processed: 4
Results of inserting each row:
  Row 1 inserted successfully
  Row 2 inserted successfully
  Row 3 inserted successfully
  Row 4 inserted successfully
Adding Batch #5...Params processed: 4
Results of inserting each row:
  Row 1 inserted successfully
  Row 2 inserted successfully
  Row 3 inserted successfully
  Row 4 inserted successfully
Commit Transaction
Free handles.

3.1.15.3.2 - Error handling during batch loads

When loading individual batches, you can find information on how many rows were accepted and what rows were rejected (see Tracking Load Status for details).

When loading individual batches, you can find information on how many rows were accepted and what rows were rejected (see Tracking load status (ODBC) for details). Other errors, such as disk space errors, do not occur while inserting individual batches. This behavior is caused by having a single COPY statement perform the loading of multiple consecutive batches. Using the single COPY statement makes the batch load process perform much faster. It is only when the COPY statement closes that the batched data is committed and Vertica reports other types of errors.

Your bulk loading application should check for errors when the COPY statement closes. Normally, you force the COPY statement to close by calling the SQLEndTran() function to end the transaction. You can also force the COPY statement to close by closing the cursor using the SQLCloseCursor() function, or by setting the database connection's AutoCommit property to true before inserting the last batch in the load.

3.1.15.4 - Using the COPY statement

COPY lets you bulk load data from a file stored on a database node into the Vertica database.

COPY lets you bulk load data from a file stored on a database node into the Vertica database. This method is the most efficient way to load data into Vertica because the file resides on the database server. You must be a superuser to use COPY to access the file system of the database node.

The following example demonstrates using the COPY command:

// Some standard headers
#include <stdio.h>
#include <stdlib.h>
// Only needed for Windows clients
// #include <windows.h>
// Standard ODBC headers
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>
// Helper function to determine if an ODBC function call returned
// successfully.
bool notSuccess(SQLRETURN ret) {
    return (ret != SQL_SUCCESS && ret != SQL_SUCCESS_WITH_INFO);
}
int main()
{
    // Set up the ODBC environment
    SQLRETURN ret;
    SQLHENV hdlEnv;
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    if(notSuccess(ret)) {
        printf("Could not allocate a handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated an environment handle.\n");
    }
    // Tell ODBC that the application uses ODBC 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
        (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    if(notSuccess(ret)) {
        printf("Could not set application version to ODBC3.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Set application to ODBC 3.\n");
    }
    // Allocate a database handle.
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    // Connect to the database
    printf("Connecting to database.\n");
    const char *dsnName = "ExampleDB";

    // Note: User MUST be a database superuser to be able to access files on the
    // filesystem of the node.
    const char* userID = "dbadmin";
    const char* passwd = "password123";
    ret = SQLConnect(hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS,(SQLCHAR*)userID,SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if(notSuccess(ret)) {
        printf("Could not connect to database.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Connected to database.\n");
    }

    // Disable AUTOCOMMIT
    printf("Disabling autocommit.\n");
    ret = SQLSetConnectAttr(hdlDbc, SQL_ATTR_AUTOCOMMIT, SQL_AUTOCOMMIT_OFF, SQL_NTS);
    if(notSuccess(ret)) {
        printf("Could not disable autocommit.\n");
        exit(EXIT_FAILURE);
    }

    // Set up a statement handle
    SQLHSTMT hdlStmt;
    SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);
    // Create table to hold the data
    SQLExecDirect(hdlStmt, (SQLCHAR*)"DROP TABLE IF EXISTS customers",
        SQL_NTS);
    SQLExecDirect(hdlStmt, (SQLCHAR*)"CREATE TABLE customers"
        "(Last_Name char(50) NOT NULL, First_Name char(50),Email char(50), "
        "Phone_Number char(15));",
        SQL_NTS);

    // Run the copy command to load data.
    ret=SQLExecDirect(hdlStmt, (SQLCHAR*)"COPY customers "
        "FROM '/data/customers.txt'",
        SQL_NTS);
    if(notSuccess(ret)) {
        printf("Data was not successfully loaded.\n");
        exit(EXIT_FAILURE);
    } else {
        // Get number of rows added.
        SQLLEN numRows;
        ret=SQLRowCount(hdlStmt, &numRows);
        printf("Successfully inserted %d rows.\n", numRows);

    }

    // Done with batches, commit the transaction
    printf("Committing transaction\n");
    ret = SQLEndTran(SQL_HANDLE_DBC, hdlDbc, SQL_COMMIT);
    if(notSuccess(ret)) {
        printf("Could not commit transaction\n");
    }  else {
        printf("Committed transaction\n");
    }

    // Clean up
    printf("Free handles.\n");
    SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    exit(EXIT_SUCCESS);
}

The example prints the following when run:

Allocated an environment handle.
Set application to ODBC 3.
Connecting to database.
Connected to database.
Disabling autocommit.
Successfully inserted 10001 rows.
Committing transaction
Committed transaction
Free handles.

3.1.15.5 - Streaming data from the client using COPY LOCAL

COPY LOCAL streams data from a client system file to your Vertica database.

COPY LOCAL streams data from a client system file to your Vertica database. This statement works through the ODBC driver, which simplifies the task of transferring data files from the client to the server.

COPY LOCAL works transparently through the ODBC driver. When a client application executes a COPY LOCAL statement, the ODBC driver reads and streams the data file from the client to the server.

This example demonstrates loading data from the client system using the COPY LOCAL statement:

// Some standard headers
#include <stdio.h>
#include <stdlib.h>
// Only needed for Windows clients
// #include <windows.h>
// Standard ODBC headers
#include <sql.h>
#include <sqltypes.h>
#include <sqlext.h>
int main()
{
    // Set up the ODBC environment
    SQLRETURN ret;
    SQLHENV hdlEnv;
    ret = SQLAllocHandle(SQL_HANDLE_ENV, SQL_NULL_HANDLE, &hdlEnv);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not allocate a handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Allocated an environment handle.\n");
    }
    // Tell ODBC that the application uses ODBC 3.
    ret = SQLSetEnvAttr(hdlEnv, SQL_ATTR_ODBC_VERSION,
        (SQLPOINTER) SQL_OV_ODBC3, SQL_IS_UINTEGER);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not set application version to ODBC3.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Set application to ODBC 3.\n");
    }
    // Allocate a database handle.
    SQLHDBC hdlDbc;
    ret = SQLAllocHandle(SQL_HANDLE_DBC, hdlEnv, &hdlDbc);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not aalocate a database handle.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Set application to ODBC 3.\n");
    }
    // Connect to the database
    printf("Connecting to database.\n");
    const char *dsnName = "ExampleDB";
    const char* userID = "dbadmin";
    const char* passwd = "password123";
    ret = SQLConnect(hdlDbc, (SQLCHAR*)dsnName,
        SQL_NTS,(SQLCHAR*)userID,SQL_NTS,
        (SQLCHAR*)passwd, SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Could not connect to database.\n");
        exit(EXIT_FAILURE);
    } else {
        printf("Connected to database.\n");
    }

    // Set up a statement handle
    SQLHSTMT hdlStmt;
    SQLAllocHandle(SQL_HANDLE_STMT, hdlDbc, &hdlStmt);


    // Create table to hold the data
    SQLExecDirect(hdlStmt, (SQLCHAR*)"DROP TABLE IF EXISTS customers",
        SQL_NTS);
    SQLExecDirect(hdlStmt, (SQLCHAR*)"CREATE TABLE customers"
        "(Last_Name char(50) NOT NULL, First_Name char(50),Email char(50), "
        "Phone_Number char(15));",
        SQL_NTS);

    // Run the copy command to load data.
    ret=SQLExecDirect(hdlStmt, (SQLCHAR*)"COPY customers "
        "FROM LOCAL '/home/dbadmin/customers.txt'",
        SQL_NTS);
    if(!SQL_SUCCEEDED(ret)) {
        printf("Data was not successfully loaded.\n");
        exit(EXIT_FAILURE);
    } else {
        // Get number of rows added.
        SQLLEN numRows;
        ret=SQLRowCount(hdlStmt, &numRows);
        printf("Successfully inserted %d rows.\n", numRows);
    }

    // COPY commits automatically, unless it is told not to, so
    // there is no need to commit the transaction.

    // Clean up
    printf("Free handles.\n");
    ret = SQLDisconnect( hdlDbc );
    if(!SQL_SUCCEEDED(ret)) {
        printf("Error disconnecting. Transaction still open?\n");
        exit(EXIT_FAILURE);
    }
    SQLFreeHandle(SQL_HANDLE_STMT, hdlStmt);
    SQLFreeHandle(SQL_HANDLE_DBC, hdlDbc);
    SQLFreeHandle(SQL_HANDLE_ENV, hdlEnv);
    exit(EXIT_SUCCESS);
}

This example is essentially the same as the example shown in Using the COPY statement, except it uses the COPY statement's LOCAL option to load data from the client system rather than from the file system of the database node.

3.2 - C#

The Vertica driver for ADO.NET allows applications written in C# to read data from, update, and load data into Vertica databases.

The Vertica driver for ADO.NET allows applications written in C# to read data from, update, and load data into Vertica databases. It provides a data adapter (Vertica Data Adapter ) that facilitates reading data from a database into a data set, and then writing changed data from the data set back to the database. It also provides a data reader ( VerticaDataReader) for reading data. The driver requires the .NET framework version 3.5+.

For more information about ADO.NET, see:

Prerequisites

You must install the ADO.NET client driver before creating C# client applications.

3.2.1 - ADO.NET data types

This table details the mapping between Vertica data types and .NET and ADO.NET data types.

This table details the mapping between Vertica data types and .NET and ADO.NET data types.

.NET Framework Type ADO.NET DbType VerticaType Vertica Data Type VerticaDataReader getter
Boolean Boolean Bit Boolean GetBoolean()
byte[] Binary

Binary

VarBinary

LongVarBinary

Binary

VarBinary

LongVarBinary

GetBytes()

Datetime DateTime

Date

Time

TimeStamp

Date

Time

TimeStamp

GetDateTime()

DateTimeOffset DateTimeOffset

TimestampTZ

TimeTZ

TimestampTZ

TimeTZ

GetDateTimeOffset()

Decimal Decimal Numeric Numeric GetDecimal()
Double Double Double

Double

Precision

GetDouble()

Int64 Int64 BigInt Integer GetInt64()
TimeSpan Object 13 Interval Types 13 Interval Types

GetInterval()

String String

Varchar

LongVarChar

Varchar

LongVarChar

GetString()
String StringFixedLengt Char Char GetString()
Guid Guid UUID (see note below) UUID GetGuid()
Object Object N/A N/A GetValue()

UUID backwards compatibility

Vertica version 9.0.0 introduced the UUID data type, including JDBC support for UUIDs. The Vertica ADO.NET, ODBC, and OLE DB clients added full support for UUIDs in version 9.0.1. Vertica maintains backwards compatibility with older supported client driver versions that do not support the UUID data type, as follows:

When an older client... Vertica...
Queries tables with UUID columns Translates the native UUID values to CHAR values.
Inserts data into a UUID column Converts the CHAR value sent by the client into a native UUID value.
Queries a UUID column's metadata Reports its data type as CHAR.

3.2.2 - Setting the locale for ADO.NET sessions

  • ADO.NET applications use a UTF-16 character set encoding and are responsible for converting any non-UTF-16 encoded data to UTF-16. The same cautions as for ODBC apply if this encoding is violated.

  • The ADO.NET driver converts UTF-16 data to UTF-8 when passing to the Vertica server and converts data sent by Vertica server from UTF-8 to UTF-16.

  • ADO.NET applications should set the correct server session locale by executing the SET LOCALE TO command in order to get expected collation and string functions behavior on the server.

  • If there is no default session locale at the database level, ADO.NET applications need to set the correct server session locale by executing the SET LOCALE TO command in order to get expected collation and string functions behavior on the server. See the SET LOCALE command.

3.2.3 - Connecting to the database

3.2.3.1 - Configuring TLS for ADO.NET

You can optionally use TLS to secure communication between your ADO.NET application and Vertica.

You can optionally use TLS to secure communication between your ADO.NET application and Vertica.

Prerequisites

Before you configure ADO.NET for TLS, you must configure client-server TLS, setting the TLSMODE to ENABLE. Mutual mode (TRY_VERIFY or higher) is not supported for ADO.NET.

Linux

The following procedure configures TLS on a Linux system:

  1. On the client filesystem, create the file /etc/ssl/certs/server.crt with the certificate text of the server certificate. You can retrieve the certificate text from a certificate in Vertica by querying the CERTIFICATES system table.
  2. Run the following command to verify that the certificate file is valid. If it is valid, the command outputs information about the certificate:
    $ openssl x509 -in /etc/ssl/certs/server.crt -text -noout
    
    Certificate:
    Data:
        Version: 3 (0x2)
        Serial Number:
            65:e7:fe:f9:0e:60:8a:79:ff:97:e2:c2:e4:e8:57:09:bd:f3:34:20
        Signature Algorithm: sha256WithRSAEncryption
        Issuer: C = US, ST = Massachusetts, L = Burlington, O = OpenText, OU = Vertica, CN = Vertica Root CA
        Validity
            Not Before: Aug  3 18:11:44 2023 GMT
            Not After : Aug 12 18:11:44 2024 GMT
        Subject: C = US, ST = Massachusetts, L = Burlington, O = OpenText, OU = Vertica, CN = *.example.com
        Subject Public Key Info:
            Public Key Algorithm: rsaEncryption
                RSA Public-Key: (2048 bit)
                Modulus:
                    00:9a:3a:83:5b:e7:73:c2:a4:15:c7:0a:81:a0:02:
                    f3:a6:6c:bb:aa:fb:fc:c8:9a:db:b9:41:21:2d:ca:
                    d9:07:1a:b1:07:35:39:0b:f3:62:08:1c:31:49:d4:
                    e2:b3:21:a8:84:eb:f4:43:5f:92:9e:c3:34:3d:4b:
                    4b:ab:ad:75:05:3c:c4:82:b5:21:45:a3:a5:c2:5c:
                    1d:c9:e3:d2:93:c1:40:b4:f6:07:f7:6c:47:68:9f:
                    9b:5d:41:4b:85:83:e0:f2:56:36:67:ee:ac:1e:08:
                    8c:6c:3a:af:b8:20:84:1d:7e:bb:d2:5e:45:d0:a8:
                    6d:ca:d8:46:5a:83:e6:d0:8d:00:fc:c1:bf:ce:d7:
                    95:4c:1d:ed:3a:45:82:d5:4d:1b:2c:d6:c4:17:5c:
                    aa:78:bc:e3:c2:2b:06:70:c3:1a:42:57:3e:19:5f:
                    7c:2f:0c:f2:d5:09:6a:ad:04:cd:95:33:92:20:56:
                    41:86:62:b2:fb:a5:d1:c5:65:cd:be:f9:31:6c:45:
                    79:a5:7f:10:7d:07:1d:26:eb:f3:18:42:14:3b:37:
                    84:81:f4:4f:c0:8d:93:b2:57:da:4f:64:53:b8:cc:
                    ed:ce:a7:c5:cc:af:5b:d1:4a:3f:fc:32:5a:f3:84:
                    89:cb:19:52:43:22:5c:9d:54:88:6b:41:3a:39:00:
                    86:bd
                Exponent: 65537 (0x10001)
        X509v3 extensions:
            X509v3 Basic Constraints:
                CA:FALSE
            X509v3 Extended Key Usage:
                TLS Web Server Authentication
            X509v3 Key Usage: critical
                Digital Signature, Key Encipherment
            X509v3 Subject Key Identifier:
                DA:39:A3:EE:5E:6B:4B:0D:32:55:BF:EF:95:60:18:90:AF:D8:07:09
            X509v3 Authority Key Identifier:
                keyid:DA:39:A3:EE:5E:6B:4B:0D:32:55:BF:EF:95:60:18:90:AF:D8:07:09
                DirName:/C=US/ST=Massachusetts/L=Burlington/O=OpenText/OU=Vertica/CN=Vertica Root CA
                serial:4C:92:49:E5:98:94:C3:9C:B9:3E:DE:30:39:ED:52:23:E6:A8:7E:D8
    
    Signature Algorithm: sha256WithRSAEncryption
         a7:f5:35:12:ef:f2:8e:7e:85:45:6a:a0:7a:64:7b:d7:82:62:
         fc:2b:b4:76:1c:5b:3e:73:f8:cb:a7:8a:07:e7:1a:f3:fc:bc:
         45:58:b0:3c:13:6f:29:fa:7b:1a:cc:7b:c7:79:bc:54:62:5c:
         3f:44:ae:7e:af:68:6d:bc:3a:38:93:3f:a6:c9:42:70:68:c3:
         39:fc:a4:1a:2f:d5:d6:5d:0f:e4:06:cb:53:61:a7:b3:44:a5:
         85:74:76:f7:b7:65:1b:74:bf:58:63:40:60:82:59:01:b7:0f:
         a4:8c:58:44:7e:41:c9:63:a2:da:92:64:0e:a0:a5:f7:ad:49:
         40:f9:e3:e4:21:f2:d3:9c:c9:06:03:d6:5d:61:ef:ef:31:49:
         e0:66:79:08:97:0e:20:ec:2f:03:6c:a1:6e:9e:3c:24:5d:da:
         cc:20:ec:29:10:92:28:b2:3d:af:fb:3a:46:7d:ca:e5:bb:48:
         57:93:ef:27:a4:4d:00:2d:6d:7c:3c:6b:55:83:af:11:ef:c3:
         2f:d2:16:09:f0:4e:45:64:8d:50:93:da:ab:07:33:fb:2b:6c:
         d2:12:16:f9:a7:3d:de:e7:b9:62:0c:c3:37:bc:51:24:e7:aa:
         64:6d:19:15:7e:f5:f0:31:e6:5c:14:56:3b:6f:f0:6b:e0:35:
         68:b1:fa:27
    
  3. On the client filesystem, create the file /usr/local/share/ca-certificates/root.crt with the certificate text of the CA certificate.
  4. Verify that the certificate was issued by the CA certificate:
    $ openssl verify -CAfile /usr/local/share/ca-certificates/root.crt /etc/ssl/certs/server.crt
    server.crt: OK
    
  5. Update the certificate store:
    $ update-ca-certificates
    

Windows

The Vertica ADO.NET driver uses the TLS certificates in the default Windows key store.

To use TLS for ADO.NET connections to Vertica:

  1. Import the server certificate into the Windows key store:
    1. Create a file server.crt with the certificate text of the server certificate.
    2. Double-click server.crt certificate file.
    3. Let Windows determine the key type and select Install.
  2. Import the CA certificate into the Windows key store:
    1. Create a file root.crt with the certificate text of the CA certificate.
    2. Double-click root.crt certificate file.
    3. Select Place all certificates in the following store.
    4. Select Browse, Trusted Root Certification Authorities, and Next.
    5. Select Install.

Enable SSL in your ADO.NET applications

In your connection string, enable SSL by setting the SSL property in VerticaConnectionStringBuilder to true, for example:

    //configure connection properties
    VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
    builder.Host = "192.168.17.10";
    builder.Database = "VMart";
    builder.User = "dbadmin";
    builder.SSL = true;
    //open the connection
    VerticaConnection _conn = new VerticaConnection(builder.ToString());
    _conn.Open();

3.2.3.2 - Opening and closing the database connection (ADO.NET)

Before you can access data in Vertica through ADO.NET, you must create a connection to the database using the VerticaConnection class which is an implementation of System.Data.DbConnection.

Before you can access data in Vertica through ADO.NET, you must create a connection to the database using the VerticaConnection class which is an implementation of System.Data.DbConnection. The VerticaConnection class takes a single argument that contains the connection properties as a string. You can manually create a string of property keywords to use as the argument, or you can use the VerticaConnectionStringBuilder class to build a connection string for you.

To download the ADO.NET driver, go to the Client Drivers Downloads page.

This topic details the following:

  • Manually building a connection string and connecting to Vertica

  • Using VerticaConnectionStringBuilder to create the connection string and connecting to Vertica

  • Closing the connection

To manually create a connection string:

See ADO.NET connection properties for a list of available properties to use in your connection string. At a minimum, you need to specify the Host, Database, and User.

  1. For each property, provide a value and append the properties and values one after the other, separated by a semicolon. Assign this string to a variable. For example:

    String connectString = "DATABASE=VMart;HOST=v_vmart_node0001;USER=dbadmin";
    
  2. Build a Vertica connection object that specifies your connection string.

    VerticaConnection _conn = new VerticaConnection(connectString)
    
  3. Open the connection.

    _conn.Open();
    
  4. Create a command object and associate it with a connection. All VerticaCommand objects must be associated with a connection.

    VerticaCommand command = _conn.CreateCommand();
    

To use the VerticaConnectionStringBuilder class to create a connection string and open a connection:

  1. Create a new object of the VerticaConnectionStringBuilder class.

    VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
    
  2. Update your VerticaConnectionStringBuilder object with property values. See ADO.NET connection properties for a list of available properties to use in your connection string. At a minimum, you need to specify the Host, Database, and User.

    builder.Host = "v_vmart_node0001";
    builder.Database = "VMart";
    builder.User = "dbadmin";
    
  3. Build a Vertica connection object that specifies your connection VerticaConnectionStringBuilder object as a string.

    VerticaConnection _conn = new VerticaConnection(builder.ToString());
    
  4. Open the connection.

    _conn.Open();
    
  5. Create a command object and associate it with a connection. All VerticaCommand objects must be associated with a connection.

    VerticaCommand command = _conn.CreateCommand;
    

To close the connection:

When you're finished with the database, close the connection. Failure to close the connection can deteriorate the performance and scalability of your application. It can also prevent other clients from obtaining locks.

 _conn.Close();

Example usage:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();
        //Perform some operations
            _conn.Close();
        }
    }
}

3.2.3.3 - ADO.NET connection properties

You use connection properties to configure the connection between your ADO.NET client application and your Vertica database.

To download the ADO.NET driver, go to the Client Drivers Downloads page.

You use connection properties to configure the connection between your ADO.NET client application and your Vertica database. The properties provide the basic information about the connections, such as the server name and port number, needed to connect to your database.

You can set a connection property in two ways:

  • Include the property name and value as part of the connection string you pass to a VerticaConnection.

  • Set the properties in a VerticaConnectionStringBuilder object, and then pass the object as a string to a VerticaConnection.

General connection properties

Property Description Default Value
Database Name of the Vertica database to which you want to connect. For example, if you installed the example VMart database, the database is "VMart". none
User Name of the user to log into Vertica. none
Port Port on which Vertica is running. 5433
Host

The host name or IP address of the server on which Vertica is running.

You can provide an IPv4 address, IPv6 address, or host name.

In mixed IPv4/IPv6 networks, the DNS server configuration determines which IP version address is sent first. Use the PreferredAddressFamily option to force the connection to use either IPv4 or IPv6.

none
PreferredAddressFamily

The IP version to use if the client and server have both IPv4 and IPv6 addresses and you have provided a host name. Valid values are:

  • Ipv4—Connect to the server using IPv4.

  • Ipv6—Connect to the server using IPv6.

  • None—Use the IP address provided by the DNS server.

Vertica.Data.VerticaClient.AddressFamilyPreference.None
Password The password associated with the user connecting to the server. string.Empty
BinaryTransfer

Provides a Boolean value that, when set to true, uses binary transfer instead of text transfer. When set to false, the ADO.NET connection uses text transfer. Binary transfer provides faster performance in reading data from a server to an ADO.NET client. Binary transfer also requires less bandwidth than text transfer, although it sometimes uses more when transferring a large number of small values.

Binary transfer mode is not backwards compatible to ADO.NET versions earlier than 3.8. If you are using an earlier version, set this value to false.

The data output by both modes is identical with the following exceptions for certain data types:

  • FLOAT: Binary transfer has slightly better precision.

  • TIMESTAMPTZ: Binary transfer can fail to get the session time zone and default to the local time zone, while text transfer reliably uses the session time zone.

  • NUMERIC: Binary transfer is forcibly disabled for NUMERIC data by the server for Vertica 11.0.2+.

true
ConnSettings SQL commands to run upon connection. Uses %3B for semicolons. string.Empty
IsolationLevel

Sets the transaction isolation level for Vertica. See Transactions for a description of the different transaction levels. This value is either Serializable, ReadCommitted, or Unspecified. See Setting the transaction isolation level for an example of setting the isolation level using this keyword.

Note: By default, this value is set to IsolationLevel.Unspecified, which means the connection uses the server's default transaction isolation level. Vertica's default isolation level is IsolationLevel.ReadCommitted.

System.Data.
IsolationLevel.Unspecified
Label A string to identify the session on the server. string
DirectBatchInsert Deprecated true
ResultBufferSize The size of the buffer to use when streaming results. A value of 0 means ResultBufferSize is turned off. 8192
ConnectionTimeout Number seconds to wait for a connection. A value of 0 means no timeout. 0
ReadOnly A Boolean value. If true, throw an exception on write attempts. false
Pooling A boolean value, whether to enable connection pooling. Connection pooling is useful for server applications because it allows the server to reuse connections. This saves resources and enhances the performance of executing commands on the database. It also reduces the amount of time a user must wait to establish a connection to the database false
MinPoolSize

An integer that defines the minimum number of connections to pool.

Valid Values: Cannot be greater than the number of connections that the server is configured to allow. Otherwise, an exception results.

Default: 55

1
MaxPoolSize

An integer that defines the maximum number of connections to pool.

Valid Values: Cannot be greater than the number of connections that the server is configured to allow. Otherwise, an exception results.

20
LoadBalanceTimeout

The amount of time, expressed in seconds, to timeout or remove unused pooled connections.

**Disable: **Set to 0 (no timeouts)

If you are using a cluster environment to load-balance the work, then pool is restricted to the servers in the cluster when the pool was created. If additional servers are added to the cluster, and the pool is not removed, then the new servers are never added to the connection pool unless LoadBalanceTimeout is set and exceeded or VerticaConnection.ClearAllPools() is called manually from an application. If you are using load balancing, then set this property to a value that considers when new servers are added to the cluster. However, do not set it so low that pools are frequently removed and rebuilt, doing so makes pooling ineffective.

0 (no timeout)
Workload The name of the workload for the session. For details, see Workload routing. None (no workload)
SSL A Boolean value, indicating whether to use SSL for the connection. false
IntegratedSecurity Provides a Boolean value that, when set to true, uses the user’s Windows credentials for authentication, instead of user/password in the connection string. false
KerberosServiceName Provides the service name portion of the Vertica Kerberos principal; for example: vertica/host@EXAMPLE.COM vertica
KerberosHostname Provides the instance or host name portion of the Vertica Kerberos principal; for example: verticaost@EXAMPLE.COM Value specified in the servername connection string property

OAuth connection properties

For details on configuring the ADO.NET driver for OAuth authentication, see Configuring OAuth authentication.

Property Description Default Value
OAuthAccessToken Required, an OAuth token that authorizes a user to the database. The client retrieves this from the identity provider and then presents it to Vertica in a connection attempt. Vertica then contacts the IDP to verify that the access token is valid. none

3.2.3.4 - Load balancing in ADO.NET

Native connection load balancing

Native connection load balancing helps spread the overhead caused by client connections on the hosts in the Vertica database. Both the server and the client must enable native connection load balancing. If enabled by both, then when the client initially connects to a host in the database, the host picks a host to handle the client connection from a list of the currently up hosts in the database, and informs the client which host it has chosen.

If the initially-contacted host does not choose itself to handle the connection, the client disconnects, then opens a second connection to the host selected by the first host. The connection process to this second host proceeds as usual—if SSL is enabled, then SSL negotiations begin, otherwise the client begins the authentication process. See About native connection load balancing for details.

To enable native load balancing on your client, set the ConnectionLoadBalance connection parameter to true either in the connection string or using the ConnectionStringBuilder(). The following example demonstrates connecting to the database several times with native connection load balancing enabled, and fetching the name of the node handling the connection from the V_MONITOR.CURRENT_SESSION system table.

using System;
using System.Text;
using System.Data;
using Vertica.Data.VerticaClient;

namespace ConsoleApplication1 {
    class Program {
        static void Main(string[] args) {
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "v_vmart_node0001.example.com";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            // Enable native client load balancing in the client,
            // must also be enabled on the server!
            builder.ConnectionLoadBalance = true;

            // Connect 3 times to verify a new node is connected
            // for each connection.
            for (int i = 1; i <= 4; i++) {
                try {
                    VerticaConnection _conn = new VerticaConnection(builder.ToString());
                    _conn.Open();
                    if (i == 1) {
                        // On the first connection, check the server policy for load balance
                        VerticaCommand sqlcom = _conn.CreateCommand();
                        sqlcom.CommandText = "SELECT LOAD_BALANCE_POLICY FROM V_CATALOG.DATABASES";
                        var returnValue = sqlcom.ExecuteScalar();
                        Console.WriteLine("Status of load balancy policy
             on server: " + returnValue.ToString() + "\n");
                    }
                    VerticaCommand command = _conn.CreateCommand();
                    command.CommandText = "SELECT node_name FROM V_MONITOR.CURRENT_SESSION";
                    VerticaDataReader dr = command.ExecuteReader();
                    while (dr.Read()) {
                        Console.Write("Connect attempt #" + i + "... ");
                        Console.WriteLine("Connected to node " + dr[0]);
                    }
                    dr.Close();
                    _conn.Close();
                    Console.WriteLine("Disconnecting.\n");
                }
                catch(Exception e) {
                    Console.WriteLine(e.Message);
                }
            }
        }
    }
}

Running the above example produces the following output:

Status of load balancing policy on server: roundrobin

Connect attempt #1... Connected to node v_vmart_node0001
Disconnecting.

Connect attempt #2... Connected to node v_vmart_node0002
Disconnecting.

Connect attempt #3... Connected to node v_vmart_node0003
Disconnecting.

Connect attempt #4... Connected to node v_vmart_node0001
Disconnecting.

Hostname-based load balancing

You can also balance workloads by resolving a single hostname to multiple IP addresses. The ADO.NET client driver load balances by automatically resolving the hostname to one of the specified IP addresses at random.

For example, suppose the hostname verticahost.example.com has the following entries in C:\Windows\System32\drivers\etc\hosts:

192.0.2.0 verticahost.example.com
192.0.2.1 verticahost.example.com
192.0.2.2 verticahost.example.com

Specifying the hostname verticahost.example.com randomly resolves to one of the listed IP addresses.

3.2.3.5 - ADO.NET connection failover

If a client application attempts to connect to a host in the Vertica cluster that is down, the connection attempt fails when using the default connection configuration. This failure usually returns an error to the user. The user must either wait until the host recovers and retry the connection or manually edit the connection settings to choose another host.

Due to Vertica Analytic Database's distributed architecture, you usually do not care which database host handles a client application's connection. You can use the client driver's connection failover feature to prevent the user from getting connection errors when the host specified in the connection settings is unreachable. The JDBC driver gives you several ways to let the client driver automatically attempt to connect to a different host if the one specified in the connection parameters is unreachable:

  • Configure your DNS server to return multiple IP addresses for a host name. When you use this host name in the connection settings, the client attempts to connect to the first IP address from the DNS lookup. If the host at that IP address is unreachable, the client tries to connect to the second IP, and so on until it either manages to connect to a host or it runs out of IP addresses.

  • Supply a list of backup hosts for the client driver to try if the primary host you specify in the connection parameters is unreachable.

  • (JDBC only) Use driver-specific connection properties to manage timeouts before attempting to connect to the next node.

For all methods, the process of failover is transparent to the client application (other than specifying the list of backup hosts, if you choose to use the list method of failover). If the primary host is unreachable, the client driver automatically tries to connect to other hosts.

Failover only applies to the initial establishment of the client connection. If the connection breaks, the driver does not automatically try to reconnect to another host in the database.

Choosing a failover method

You usually choose to use one of the two failover methods. However, they do work together. If your DNS server returns multiple IP addresses and you supply a list of backup hosts, the client first tries all of the IPs returned by the DNS server, then the hosts in the backup list.

The DNS method of failover centralizes the configuration client failover. As you add new nodes to your Vertica Analytic Database cluster, you can choose to add them to the failover list by editing the DNS server settings. All client systems that use the DNS server to connect to Vertica Analytic Database automatically use connection failover without having to change any settings. However, this method does require administrative access to the DNS server that all clients use to connect to the Vertica Analytic Database cluster. This may not be possible in your organization.

Using the backup server list is easier than editing the DNS server settings. However, it decentralizes the failover feature. You may need to update the application settings on each client system if you make changes to your Vertica Analytic Database cluster.

Using DNS failover

To use DNS failover, you need to change your DNS server's settings to map a single host name to multiple IP addresses of hosts in your Vertica Analytic Database cluster. You then have all client applications use this host name to connect to Vertica Analytic Database.

You can choose to have your DNS server return as many IP addresses for the host name as you want. In smaller clusters, you may choose to have it return the IP addresses of all of the hosts in your cluster. However, for larger clusters, you should consider choosing a subset of the hosts to return. Otherwise there can be a long delay as the client driver tries unsuccessfully to connect to each host in a database that is down.

Using the backup host list

To enable backup list-based connection failover, your client application has to specify at least one IP address or host name of a host in the BackupServerNode parameter. The host name or IP can optionally be followed by a colon and a port number. If not supplied, the driver defaults to the standard Vertica port number (5433). To list multiple hosts, separate them by a comma.

The following example demonstrates setting the BackupServerNode connection parameter to specify additional hosts for the connection attempt. The connection string intentionally has a non-existent node, so that the initial connection fails. The client driver has to resort to trying the backup hosts to establish a connection to Vertica.

using System;
using System.Text;
using System.Data;
using Vertica.Data.VerticaClient;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            VerticaConnectionStringBuilder builder =
        new VerticaConnectionStringBuilder();
            builder.Host = "not.a.real.host:5433";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            builder.BackupServerNode =
        "another.broken.node:5433,v_vmart_node0002.example.com:5433";
            try
            {
                VerticaConnection _conn =
            new VerticaConnection(builder.ToString());
                _conn.Open();
                VerticaCommand sqlcom = _conn.CreateCommand();
                sqlcom.CommandText = "SELECT node_name FROM current_session";
                var returnValue = sqlcom.ExecuteScalar();
                Console.WriteLine("Connected to node: " +
            returnValue.ToString() + "\n");
                _conn.Close();
                Console.WriteLine("Disconnecting.\n");
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
        }
    }
}

Notes

  • When native connection load balancing is enabled, the additional servers specified in the BackupServerNode connection parameter are only used for the initial connection to a Vertica host. If host redirects the client to another host in the database cluster to handle its connection request, the second connection does not use the backup node list. This is rarely an issue, since native connection load balancing is aware of which nodes are currently up in the database. See Load balancing in ADO.NET.

  • Connections to a host taken from the BackupServerNode list are not pooled for ADO.NET connections.

3.2.4 - Querying the database using ADO.NET

This section describes how to create queries to do the following:.

This section describes how to create queries to do the following:

3.2.4.1 - Inserting data (ADO.NET)

Inserting data can done using the VerticaCommand class.

Inserting data can done using the VerticaCommand class. VerticaCommand is an implementation of DbCommand. It allows you to create and send a SQL statement to the database. Use the CommandText method to assign a SQL statement to the command and then execute the SQL by calling the ExecuteNonQuery method. The ExecuteNonQuery method is used for executing statements that do not return result sets.

To insert a single row of data:

  1. Create a connection to the database.

  2. Create a command object using the connection.

    VerticaCommand command = _conn.CreateCommand();
    
  3. Insert data using an INSERT statement. The following is an example of a simple insert. Note that is does not contain a COMMIT statement because the Vertica ADO.NET driver operates in autocommit mode.

    command.CommandText =
         "INSERT into test values(2, 'username', 'email', 'password')";
    
  4. Execute the query. The rowsAdded variable contains the number of rows added by the insert statement.

    Int32 rowsAdded = command.ExecuteNonQuery();
    

    The ExecuteNonQuery() method returns the number of rows affected by the command for UPDATE, INSERT, and DELETE statements. For all other types of statements it returns -1. If a rollback occurs then it is also set to -1.

Example usage:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();
        VerticaCommand command = _conn.CreateCommand();
        command.CommandText =
               "INSERT into test values(2, 'username', 'email', 'password')";
        Int32 rowsAdded = command.ExecuteNonQuery();
        Console.WriteLine( rowsAdded + " rows added!");
            _conn.Close();
        }
    }
}

3.2.4.1.1 - Using parameters

You can use parameters to execute similar SQL statements repeatedly and efficiently.

You can use parameters to execute similar SQL statements repeatedly and efficiently.

Using parameters

VerticaParameters are an extension of the System.Data.DbParameter base class in ADO.NET and are used to set parameters in commands sent to the server. Use Parameters in all queries (SELECT/INSERT/UPDATE/DELETE) for which the values in the WHERE clause are not static; that is for all queries that have a known set of columns, but whose filter criteria is set dynamically by an application or end user. Using parameters in this way greatly decreases the chances of a SQL injection issue that can occur when simply creating a SQL query from a number of variables.

Parameters require that a valid DbType, VerticaDbType, or System type be assigned to the parameter. See Data types and ADO.NET data types for a mapping of System, Vertica, and DbTypes.

To create a parameter placeholder, place either the at sign (@) or a colon (:) character in front of the parameter name in the actual query string. Do not insert any spaces between the placeholder indicator (@ or :) and the placeholder.

For example, the following typical query uses the string 'MA' as a filter.

SELECT customer_name, customer_address, customer_city, customer_state
FROM customer_dimension WHERE customer_state = 'MA';

Instead, the query can be written to use a parameter. In the following example, the string MA is replaced by the parameter placeholder @STATE.

SELECT customer_name, customer_address, customer_city, customer_state
FROM customer_dimension WHERE customer_state = @STATE;

For example, the ADO.net code for the prior example would be written as:

VerticaCommand command = _conn.CreateCommand();
command.CommandText = “SELECT customer_name, customer_address, customer_city, customer_state
    FROM customer_dimension WHERE customer_state = @STATE”;
command.Parameters.Add(new VerticaParameter( “STATE”, VerticaType.VarChar));
command.Parameters["STATE"].Value = "MA";

3.2.4.1.2 - Creating and rolling back transactions

Transactions in Vertica are atomic, consistent, isolated, and durable.

Creating transactions

Transactions in Vertica are atomic, consistent, isolated, and durable. When you connect to a database using the Vertica ADO.NET Driver, the connection is in autocommit mode and each individual query is committed upon execution. You can collect multiple statements into a single transaction and commit them at the same time by using a transaction. You can also choose to rollback a transaction before it is committed if your code determines that a transaction should not commit.

Transactions use the VerticaTransaction object, which is an implementation of DbTransaction. You must associate the transaction with the VerticaCommand object.

The following code uses an explicit transaction to insert one row each into to tables of the VMart schema.

To create a transaction in Vertica using the ADO.NET driver:

  1. Create a connection to the database.

  2. Create a command object using the connection.

    VerticaCommand command = _conn.CreateCommand();
    
  3. Start an explicit transaction, and associate the command with it.

    VerticaTransaction txn = _conn.BeginTransaction();
    command.Connection = _conn;
    command.Transaction = txn;
    
  4. Execute the individual SQL statements to add rows.

    command.CommandText =
         "insert into product_dimension values( ... )";
    command.ExecuteNonQuery();
    command.CommandText =
         "insert into store_orders_fact values( ... )";
    
  5. Commit the transaction.

    txn.Commit();
    

Rolling back transactions

If your code checks for errors, then you can catch the error and rollback the entire transaction.

VerticaTransaction txn = _conn.BeginTransaction();
VerticaCommand command = new
        VerticaCommand("insert into product_dimension values( 838929, 5, 'New item 5' )", _conn);
// execute the insert
command.ExecuteNonQuery();
command.CommandText = "insert into product_dimension values( 838929, 6, 'New item 6' )";
// try insert and catch any errors
bool error = false;
try
{
    command.ExecuteNonQuery();
}
catch (Exception e)
{
    Console.WriteLine(e.Message);
    error = true;
}
if (error)
{
    txn.Rollback();
    Console.WriteLine("Errors. Rolling Back.");
}
else
{
    txn.Commit();
    Console.WriteLine("Queries Successful. Committing.");
}

Commit and rollback example

This example details how you can commit or rollback queries during a transaction.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();
            bool error = false;
                VerticaCommand command = _conn.CreateCommand();
                VerticaCommand command2 = _conn.CreateCommand();
                VerticaTransaction txn = _conn.BeginTransaction();
                command.Connection = _conn;
                command.Transaction = txn;
                command.CommandText =
                "insert into test values(1, 'test', 'test', 'test' )";
                Console.WriteLine(command.CommandText);
                try
                {
                    command.ExecuteNonQuery();
                }
                catch (Exception e)
                {
                    Console.WriteLine(e.Message);
                    error = true;
                }
                command.CommandText =
                "insert into test values(2, 'ear', 'eye', 'nose', 'extra' )";
                Console.WriteLine(command.CommandText);
                try
                {
                    command.ExecuteNonQuery();
                }
                catch (Exception e)
                {
                    Console.WriteLine(e.Message);
                    error = true;
                }
                if (error)
                {
                    txn.Rollback();
                    Console.WriteLine("Errors. Rolling Back.");
                }
                else
                {
                    txn.Commit();
                    Console.WriteLine("Queries Successful. Committing.");
                }
            _conn.Close();
        }
    }
}

The example displays the following output on the console:

insert into test values(1, 'test', 'test', 'test' )
insert into test values(2, 'ear', 'eye', 'nose', 'extra' )
[42601]ERROR: INSERT has more expressions than target columns
Errors. Rolling Back.

See also

3.2.4.1.2.1 - Setting the transaction isolation level

You can set the transaction isolation level on a per-connection and per-transaction basis.

You can set the transaction isolation level on a per-connection and per-transaction basis. See Transaction for an overview of the transaction isolation levels supported in Vertica. To set the default transaction isolation level for a connection, use the IsolationLevel keyword in the VerticaConnectionStringBuilder string (see Connection String Keywords for details). To set the isolation level for an individual transaction, pass the isolation level to the VerticaConnection.BeginTransaction() method call to start the transaction.

To set the isolation level on a connection-basis:

  1. Use the VerticaConnectionStringBuilder to build the connection string.

  2. Provide a value for the IsolationLevel builder string. It can take one of two values: IsolationLevel.ReadCommited (default) or IsolationLevel.Serializeable. For example:

        VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
        builder.Host = "192.168.1.100";
        builder.Database = "VMart";
        builder.User = "dbadmin";
        builder.IsolationLevel = System.Data.IsolationLevel.Serializeable
        VerticaConnection _conn1 = new VerticaConnection(builder.ToString());
        _conn1.Open();
    

To set the isolation level on a transaction basis:

  1. Set the IsolationLevel on the BeginTransaction method, for example

    VerticaTransaction txn = _conn.BeginTransaction(IsolationLevel.Serializable);
    

Example usage:

The following example demonstrates:

  • getting the connection's transaction isolation level.

  • setting the connection's isolation level using connection property.

  • setting the transaction isolation level for a new transaction.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            VerticaConnection _conn1 = new VerticaConnection(builder.ToString());
             _conn1.Open();
            VerticaTransaction txn1 = _conn1.BeginTransaction();
            Console.WriteLine("\n Transaction 1 Transaction Isolation Level: " +
             txn1.IsolationLevel.ToString());
            txn1.Rollback();
            VerticaTransaction txn2 = _conn1.BeginTransaction(IsolationLevel.Serializable);
            Console.WriteLine("\n Transaction 2 Transaction Isolation Level: " +
             txn2.IsolationLevel.ToString());
            txn2.Rollback();
            VerticaTransaction txn3 = _conn1.BeginTransaction(IsolationLevel.ReadCommitted);
            Console.WriteLine("\n Transaction 3 Transaction Isolation Level: " +
             txn3.IsolationLevel.ToString());
            _conn1.Close();
        }
    }
}

When run, the example code prints the following to the system console:

 Transaction 1 Transaction Isolation Level: ReadCommitted
 Transaction 2 Transaction Isolation Level: Serializable
 Transaction 3 Transaction Isolation Level: ReadCommitted

3.2.4.2 - Reading data (ADO.Net)

To read data from the database use VerticaDataReader, an implementation of DbDataReader.

To read data from the database use VerticaDataReader, an implementation of DbDataReader. This implementation is useful for moving large volumes of data quickly off the server where it can be run through analytic applications.

To read data from the database using VerticaDataReader:

  1. Create a connection to the database.

  2. Create a command object using the connection.

        VerticaCommand command = _conn.CreateCommand();
    
  3. Create a query. This query works with the example VMart database.

            command.CommandText =
            "SELECT fat_content, product_description " +
            "FROM (SELECT DISTINCT fat_content, product_description" +
            "      FROM product_dimension " +
            "      WHERE department_description " +        "      IN ('Dairy') " +
            "      ORDER BY fat_content) AS food " +
            "LIMIT 10;";
    
  4. Execute the reader to return the results from the query. The following command calls the ExecuteReader method of the VerticaCommand object to obtain the VerticaDataReader object.

    VerticaDataReader dr = command.ExecuteReader();
    
  5. Read the data. The data reader returns results in a sequential stream. Therefore, you must read data from tables row-by-row. The following example uses a while loop to accomplish this:

     Console.WriteLine("\n\n Fat Content\t  Product Description");
         Console.WriteLine("------------\t  -------------------");
         int rows = 0;
         while (dr.Read())
         {
            Console.WriteLine("     " + dr[0] + "    \t  " + dr[1]);
            ++rows;
         }
         Console.WriteLine("------------\n  (" + rows + " rows)\n");
    
  6. When you're finished, close the data reader to free up resources.

        dr.Close();
    

Example usage:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();
        VerticaCommand command = _conn.CreateCommand();
            command.CommandText =
                "SELECT fat_content, product_description " +
                "FROM (SELECT DISTINCT fat_content, product_description" +
                "      FROM product_dimension " +
                "      WHERE department_description " +
                "      IN ('Dairy') " +
                "      ORDER BY fat_content) AS food " +
                "LIMIT 10;";
          VerticaDataReader dr = command.ExecuteReader();

         Console.WriteLine("\n\n Fat Content\t  Product Description");
         Console.WriteLine("------------\t  -------------------");
         int rows = 0;
         while (dr.Read())
         {
                Console.WriteLine("     " + dr[0] + "    \t  " + dr[1]);
                ++rows;
         }
         Console.WriteLine("------------\n  (" + rows + " rows)\n");
              dr.Close();
            _conn.Close();
        }
    }
}

3.2.4.3 - Loading data through ADO.Net

This section details the different ways that you can load data in Vertica using the ADO.NET client driver:.

This section details the different ways that you can load data in Vertica using the ADO.NET client driver:

3.2.4.3.1 - Using the Vertica data adapter

The Vertica data adapter (VerticaDataAdapter) enables a client to exchange data between a data set and a Vertica database.

The Vertica data adapter (VerticaDataAdapter) enables a client to exchange data between a data set and a Vertica database. It is an implementation of DbDataAdapter. You can use VerticaDataAdapter to simply read data, or, for example, read data from a database into a data set, and then write changed data from the data set back to the database.

Batching updates

When using the Update() method to update a dataset, you can optionally use the UpdateBatchSize() method prior to calling Update() to reduce the number of times the client communicates with the server to perform the update. The default value of UpdateBatchSize is 1. If you have multiple rows.Add() commands for a data set, then you can change the batch size to an optimal size to speed up the operations your client must perform to complete the update.

Reading data from Vertica using the data adapter:

The following example details how to perform a select query on the VMart schema and load the result into a DataTable, then output the contents of the DataTable to the console.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;
Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();

            // Try/Catch any exceptions
                   try
            {
                using (_conn)
                {
                    // Create the command
                    VerticaCommand command = _conn.CreateCommand();
                    command.CommandText = "select product_key, product_description " +
                        "from product_dimension where product_key < 10";

                        // Associate the command with the connection
                        command.Connection = _conn;

                        // Create the DataAdapter
                        VerticaDataAdapter adapter = new VerticaDataAdapter();
                        adapter.SelectCommand = command;

                        // Fill the DataTable
                        DataTable table = new DataTable();
                        adapter.Fill(table);

                        //  Display each row and column value.
                        int i = 1;
                        foreach (DataRow row in table.Rows)
                        {
                            foreach (DataColumn column in table.Columns)
                            {
                                Console.Write(row[column] + "\t");
                            }
                            Console.WriteLine();
                            i++;
                        }
                    Console.WriteLine(i + " rows returned.");
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            _conn.Close();
        }
    }
}

Reading data from Vertica into a data set and changing data:

The following example shows how to use a data adapter to read from and insert into a dimension table of the VMart schema.


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using Vertica.Data.VerticaClient
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();

                  // Try/Catch any exceptions
                    try
            {
                using (_conn)
                {

                            //Create a data adapter object using the connection
                            VerticaDataAdapter da = new VerticaDataAdapter();

                            //Create a select statement that retrieves data from the table
                            da.SelectCommand = new
                        VerticaCommand("select * from product_dimension where product_key < 10",
                        _conn);
                            //Set up the insert command for the data adapter, and bind variables for some of the columns
                            da.InsertCommand = new
                        VerticaCommand("insert into product_dimension values( :key, :version, :desc )",
                        _conn);
                    da.InsertCommand.Parameters.Add(new VerticaParameter("key", VerticaType.BigInt));
                    da.InsertCommand.Parameters.Add(new VerticaParameter("version", VerticaType.BigInt));
                    da.InsertCommand.Parameters.Add(new VerticaParameter("desc", VerticaType.VarChar));
                    da.InsertCommand.Parameters[0].SourceColumn = "product_key";
                    da.InsertCommand.Parameters[1].SourceColumn = "product_version";
                    da.InsertCommand.Parameters[2].SourceColumn = "product_description";
                    da.TableMappings.Add("product_key", "product_key");
                    da.TableMappings.Add("product_version", "product_version");
                    da.TableMappings.Add("product_description", "product_description");

                            //Create and fill a Data set for this dimension table, and get the resulting DataTable.
                            DataSet ds = new DataSet();
                    da.Fill(ds, 0, 0, "product_dimension");
                    DataTable dt = ds.Tables[0];

                            //Bind parameters and add two rows to the table.
                            DataRow dr = dt.NewRow();
                    dr["product_key"] = 838929;
                    dr["product_version"] = 5;
                    dr["product_description"] = "New item 5";
                    dt.Rows.Add(dr);
                    dr = dt.NewRow();
                    dr["product_key"] = 838929;
                    dr["product_version"] = 6;
                    dr["product_description"] = "New item 6";
                    dt.Rows.Add(dr);
                    //Extract the changes for the added rows.
                            DataSet ds2 = ds.GetChanges();

                            //Send the modifications to the server.
                            int updateCount = da.Update(ds2, "product_dimension");

                           //Merge the changes into the original Data set, and mark it up to date.
                            ds.Merge(ds2);
                    ds.AcceptChanges();
                    Console.WriteLine(updateCount + " updates made!");
                }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }
            _conn.Close();
        }
    }
}

3.2.4.3.2 - Using batch inserts and prepared statements

You can load data in batches using a prepared statement with parameters.

You can load data in batches using a prepared statement with parameters. You can also use transactions to rollback the batch load if any errors are encountered.

If you are loading large batches of data (more than 100MB), then consider using a direct batch insert.

The following example details using data contained in arrays, parameters, and a transaction to batch load data.

The test table used in the example is created with the command:

=> CREATE TABLE test (id INT, username VARCHAR(24), email VARCHAR(64), password VARCHAR(8));

Example batch insert using parameters and transactions


using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();
            // Create arrays for column data
                    int[] ids = {1, 2, 3, 4};
            string[] usernames = {"user1", "user2", "user3", "user4"};
            string[] emails = { "user1@example.com", "user2@example.com","user3@example.com","user4@example.com" };
            string[] passwords = { "pass1", "pass2", "pass3", "pass4" };
            // create counters for accepted and rejected rows
                    int rows = 0;
            int rejRows = 0;
            bool error = false;
            // Create the transaction
                    VerticaTransaction txn = _conn.BeginTransaction();
            // Create the parameterized query and assign parameter types
                    VerticaCommand command = _conn.CreateCommand();
            command.CommandText = "insert into TEST values (@id, @username, @email, @password)";
            command.Parameters.Add(new VerticaParameter("id", VerticaType.BigInt));
            command.Parameters.Add(new VerticaParameter("username", VerticaType.VarChar));
            command.Parameters.Add(new VerticaParameter("email", VerticaType.VarChar));
            command.Parameters.Add(new VerticaParameter("password", VerticaType.VarChar));
            // Prepare the statement
                    command.Prepare();

                    // Loop through the column arrays and insert the data
                    for (int i = 0; i < ids.Length; i++)            {
                command.Parameters["id"].Value = ids[i];
                command.Parameters["username"].Value = usernames[i];
                command.Parameters["email"].Value = emails[i];
                command.Parameters["password"].Value = passwords[i];
                try
                {
                    rows += command.ExecuteNonQuery();
                }
                catch (Exception e)
                {
                    Console.WriteLine("\nInsert failed - \n  " + e.Message + "\n");
                    ++rejRows;
                    error = true;
                }
            }
            if (error)
            {
                // Roll back if errors
                        Console.WriteLine("Errors. Rolling Back Transaction.");
                Console.WriteLine(rejRows + " rows rejected.");
                txn.Rollback();
            }
            else
            {
                // Commit if no errors
                        Console.WriteLine("No Errors. Committing Transaction.");
                txn.Commit();
                Console.WriteLine("Inserted " + rows + " rows. ");
            }
            _conn.Close();
        }
    }
}

3.2.4.3.3 - Streaming data via ADO.NET

There are two options to stream data from a file on the client to your Vertica database through ADO.NET:.

There are two options to stream data from a file on the client to your Vertica database through ADO.NET:

  • Use the VerticaCopyStream ADO.NET class to stream data in an object-oriented manner

  • Execute a COPY LOCAL SQL statement to stream the data

The topics in this section explain how to use these options.

3.2.4.3.3.1 - Streaming from the client via VerticaCopyStream

The VerticaCopyStream class lets you stream data from the client system to a Vertica database.

The VerticaCopyStream class lets you stream data from the client system to a Vertica database. It lets you use the SQL COPY statement directly without having to copy the data to a host in the database cluster first by substituting one or more data stream(s) for STDIN.

Notes:

  • Use Transactions and disable auto commit on the copy command for better performance.

  • Disable auto commit using the copy command with the 'no commit' modifier. You must explicitly disable commits. Enabling transactions does not disable autocommit when using VerticaCopyStream.

  • The copy command used with VerticaCopyStream uses copy syntax.

  • VerticaCopyStream.rejects is zeroed every time execute is called. If you want to capture the number of rejects, assign the value of VerticaCopyStream.rejects to another variable before calling execute again.

  • You can add multiple streams using multiple AddStream() calls.

Example usage:

The following example demonstrates using VerticaCopyStream to copy a file stream into Vertica.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.IO;
using Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            // Configure connection properties
                    VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
                builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";
            //open the connection
            VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();
            try
            {
                using (_conn)
                {
                    // Start a transaction
                            VerticaTransaction txn = _conn.BeginTransaction();

                            // Create a table for this example
                            VerticaCommand command = new VerticaCommand("DROP TABLE IF EXISTS copy_table", _conn);
                command.ExecuteNonQuery();
                    command.CommandText = "CREATE TABLE copy_table (Last_Name char(50), "
                                    + "First_Name char(50),Email char(50), "
                                    + "Phone_Number char(15))";
                    command.ExecuteNonQuery();
                    // Create a new filestream from the data file
                            string filename = "C:/customers.txt";
                 Console.WriteLine("\n\nLoading File: " + filename);
                    FileStream inputfile = File.OpenRead(filename);
                    // Define the copy command
                            string copy = "copy copy_table from stdin record terminator E'\n' delimiter '|'" + " enforcelength "
                        + " no commit";
                    // Create a new copy stream instance with the connection and copy statement
                            VerticaCopyStream vcs = new VerticaCopyStream(_conn, copy);

                            // Start the VerticaCopyStream process
                            vcs.Start();
                            // Add the file stream
                            vcs.AddStream(inputfile, false);

                            // Execute the copy
                            vcs.Execute();

                            // Finish stream and write out the list of inserted and rejected rows
                            long rowsInserted = vcs.Finish();
                IList<long> rowsRejected = vcs.Rejects;
                // Does not work when rejected or exceptions defined
                    Console.WriteLine("Number of Rows inserted: " + rowsInserted);
                    Console.WriteLine("Number of Rows rejected: " + rowsRejected.Count);
                    if (rowsRejected.Count > 0)
                    {
                        for (int i = 0; i < rowsRejected.Count; i++)
                        {
                            Console.WriteLine("Rejected row #{0} is row {1}", i, rowsRejected[i]);
                        }
                    }

                            // Commit the changes
                            txn.Commit();
            }
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
            }


                    //close the connection
                    _conn.Close();
    }
    }
}

3.2.4.3.3.2 - Using copy with ADO.NET

To use COPY with ADO.NET, just execute a COPY statement and the path to the source file on the client system.

To use COPY with ADO.NET, just execute a COPY statement and the path to the source file on the client system. This method is simpler than using the VerticaCopyStream class. However, you may prefer using VerticaCopyStream if you have many files to copy to the database or if your data comes from a source other than a local file (streamed over a network connection, for example).

The following example code demonstrates using COPY to copy a file from the client to the database. It is the same as the code shown in Bulk Loading Using the COPY Statement and the path to the data file is on the client system, rather than on the server.

To load data that is stored on a database node, use a VerticaCommand object to create a COPY command:

  1. Create a connection to the database through the node on which the data file is stored.

  2. Create a command object using the connection.

    VerticaCommand command = _conn.CreateCommand();
    
  3. Copy data. The following is an example of using the COPY command to load data. It uses the LOCAL modifier to copy a file local to the client issuing the command.

    command.CommandText = "copy lcopy_table from '/home/dbadmin/customers.txt'"
      + " record terminator E'\n' delimiter '|'"
      + " enforcelength ";
    
    Int32 insertedRows = command.ExecuteNonQuery();
    Console.WriteLine(insertedRows + " inserted.");
    

Example usage:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.IO;
using Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            // Configure connection properties
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
     builder.Host = "192.168.1.10";
        builder.Database = "VMart";
        builder.User = "dbadmin";

                   // Open the connection
                    VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();
            try
            {
                using (_conn)
                {

                            // Start a transaction
                            VerticaTransaction txn = _conn.BeginTransaction();

                            // Create a table for this example
                            VerticaCommand command = new VerticaCommand("DROP TABLE IF EXISTS lcopy_table", _conn);
                    command.ExecuteNonQuery();
                    command.CommandText = "CREATE TABLE IF NOT EXISTS lcopy_table (Last_Name char(50), "
                                    + "First_Name char(50),Email char(50), "
                                    + "Phone_Number char(15))";
                    command.ExecuteNonQuery();
                    // Define the copy command
                            command.CommandText = "copy lcopy_table from '/home/dbadmin/customers.txt'"
            + " record terminator E'\n' delimiter '|'"
                        + " enforcelength "
                + " no commit";
                            // Execute the copy
        Int32 insertedRows = command.ExecuteNonQuery();
Console.WriteLine(insertedRows + " inserted.");
                            // Commit the changes
                            txn.Commit();
                }
            }
            catch (Exception e)
            {
                Console.WriteLine("Exception: " + e.Message);
            }


                    // Close the connection
                    _conn.Close();
        }
    }
}

3.2.5 - Canceling ADO.NET queries

You can cancel a running vsql query by calling the .Cancel() method of any Command object.

You can cancel a running vsql query by calling the .Cancel() method of any Command object. The SampleCancelTests class demonstrates how to cancel a query after reading a specified number of rows. It implements the following methods:

  • SampleCancelTest() executes the Setup() function to create a test table. Then, it calls RunQueryAndCancel() and RunSecondQuery() to demonstrate how to cancel a query after it reads a specified number of rows. Finally, it runs the Cleanup() function to drop the test table.
  • Setup() creates a database for the example queries.
  • Cleanup() drops the database.
  • RunQueryAndCancel() reads exactly 100 rows from a query that returns more than 100 rows.
  • RunSecondQuery() reads all rows from a query.
using System;
using Vertica.Data.VerticaClient;

class SampleCancelTests
{
    // Creates a database table, executes a query that cancels during a read loop,
    // executes a query that does not cancel, then drops the test database table.
    // connection: A connection to a Vertica database.

    public static void SampleCancelTest(VerticaConnection connection)
    {
        VerticaCommand command = connection.CreateCommand();

        Setup(command);

        try
        {
            Console.WriteLine("Running query that will cancel after reading 100 rows...");
            RunQueryAndCancel(command);
            Console.WriteLine("Running a second query...");
            RunSecondQuery(command);
            Console.WriteLine("Finished!");
        }
        finally
        {
            Cleanup(command);
        }
    }

    // Set up the database table for the example.
    // command: A Command object used to execute the query.
    private static void Setup(VerticaCommand command)
    {
        // Create table used for test.
        Console.WriteLine("Creating and loading table...");
        command.CommandText = "DROP TABLE IF EXISTS adocanceltest";
        command.ExecuteNonQuery();
        command.CommandText = "CREATE TABLE adocanceltest(id INTEGER, time TIMESTAMP)";
        command.ExecuteNonQuery();
        command.CommandText = @"INSERT INTO adocanceltest
        SELECT row_number() OVER(), slice_time
            FROM(
                    SELECT slice_time FROM(
                    SELECT '2021-01-01'::timestamp s UNION ALL SELECT '2022-01-01'::timestamp s
                    ) sq TIMESERIES slice_time AS '1 second' OVER(ORDER BY s)
            ) sq2";
        command.ExecuteNonQuery();
    }

    // Clean up the database after running the example.
    // command: A Command object used to execute the query.
    private static void Cleanup(VerticaCommand command)
    {
        command.CommandText = "DROP TABLE IF EXISTS adocanceltest";
        command.ExecuteNonQuery();
    }

    // Execute a query that returns many rows and cancels after reading 100.
    // command: A Command object used to execute the query.
    private static void RunQueryAndCancel(VerticaCommand command)
    {
        command.CommandText = "SELECT COUNT(id) from adocanceltest";
        int fullRowCount = Convert.ToInt32(command.ExecuteScalar());

        command.CommandText = "SELECT id, time FROM adocanceltest";
        VerticaDataReader dr = command.ExecuteReader();
        int nCount = 0;
        try
        {
            while (dr.Read())
            {
                nCount++;
                if (nCount == 100)
                {
                    // After reaching 100 rows, cancel the command
                    // Note that it is not necessary to read the remaining rows
                    command.Cancel();
                    return;
                }
            }
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
        }
        finally
        {
            dr.Close();
            // Verify that the cancel stopped the query
            Console.WriteLine((fullRowCount - nCount) + " rows out of " + fullRowCount + " discarded by cancel");
        }
    }

    // Execute a simple query and read all results.
    // command: A Command object used to execute the query.
    private static void RunSecondQuery(VerticaCommand command)
    {
        command.CommandText = "SELECT 1 FROM dual";
        VerticaDataReader dr = command.ExecuteReader();
        try
        {
            while (dr.Read())
            {
                ;
            }
        }
        catch (Exception e)
        {
            Console.WriteLine(e.Message);
            Console.WriteLine("Warning: no exception should be thrown on query after cancel");
        }
        finally
        {
            dr.Close();
        }
    }
}

3.2.6 - Handling messages

You can capture info and warning messages that Vertica provides to the ADO.NET driver by using the InfoMessage event on the VerticaConnection delegate class.

You can capture info and warning messages that Vertica provides to the ADO.NET driver by using the InfoMessage event on the VerticaConnection delegate class. This class captures messages that are not severe enough to force an exception to be triggered, but might still provide information that can benefit your application.

To use the VerticaInfoMessageEventHander class:

  1. Create a method to handle the message sent from the even handler:

    static void conn_InfoMessage(object sender, VerticaInfoMessageEventArgs e)
    {
        Console.WriteLine(e.SqlState + ": " + e.Message);
    }
    
  2. Create a connection and register a new VerticaInfoMessageHandler delegate for the InfoMessage event:

    _conn.InfoMessage += new VerticaInfoMessageEventHandler(conn_InfoMessage);
    
  3. Execute your queries. If a message is generated, then the event handle function is run.

  4. You can unsubscribe from the event with the following command:

    _conn.InfoMessage -= new VerticaInfoMessageEventHandler(conn_InfoMessage);
    

Examples

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Vertica.Data.VerticaClient;
namespace ConsoleApplication {
  class Program {
    // define message handler to deal with messages
    static void conn_InfoMessage(object sender, VerticaInfoMessageEventArgs e) {
      Console.WriteLine(e.SqlState + ": " + e.Message);
    }
    static void Main(string[] args) {
      //configure connection properties
      VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
      builder.Host = "192.168.1.10";
      builder.Database = "VMart";
      builder.User = "dbadmin";

      //open the connection
      VerticaConnection _conn = new VerticaConnection(builder.ToString());
      _conn.Open();

      //create message handler instance by subscribing it to the InfoMessage event of the connection
      _conn.InfoMessage += new VerticaInfoMessageEventHandler(conn_InfoMessage);

      //create and execute the command
      VerticaCommand cmd = _conn.CreateCommand();
      cmd.CommandText = "drop table if exists fakeTable";
      cmd.ExecuteNonQuery();

      //close the connection
      _conn.Close();
    }
  }
}

This examples displays the following when run:

00000: Nothing was dropped

3.2.7 - Getting table metadata

You can get the table metadata by using the GetSchema() method on a connection and loading the metadata into a DataTable:.

You can get the table metadata by using the GetSchema() method on a connection and loading the metadata into a DataTable:

  • database_name, schema_name, and table_name can be set to null, a specific name, or use a LIKE pattern.

  • table_type can be one of:

    • "SYSTEM TABLE"

    • "TABLE"

    • "GLOBAL TEMPORARY"

    • "LOCAL TEMPORARY"

    • "VIEW"

    • null

  • If table_type is null, then the metadata for all metadata tables is returned.

For example:

DataTable table = _conn.GetSchema("Tables", new string[] { null, null, null, "SYSTEM TABLE" });

Examples

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using Vertica.Data.VerticaClient;
namespace ConsoleApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            // configure connection properties
            VerticaConnectionStringBuilder builder = new VerticaConnectionStringBuilder();
            builder.Host = "192.168.1.10";
            builder.Database = "VMart";
            builder.User = "dbadmin";

            // open the connection
            VerticaConnection _conn = new VerticaConnection(builder.ToString());
            _conn.Open();

            // create a new data table containing the schema
            // the last argument can be "SYSTEM TABLE", "TABLE", "GLOBAL TEMPORARY",
            // "LOCAL TEMPORARY", "VIEW", or null for all types
            DataTable table = _conn.GetSchema("Tables", new string[] { null, null, null, "SYSTEM TABLE" });

            // print out the schema
            foreach (DataRow row in table.Rows) {
                foreach (DataColumn col in table.Columns)
                {
                    Console.WriteLine("{0} = {1}", col.ColumnName, row[col]);
                }
                Console.WriteLine("============================");
            }

            //close the connection
            _conn.Close();
        }
    }
}

3.3 - Go

The open-source vertica-sql-go driver lets you interact with your database with Go.

The open-source vertica-sql-go driver lets you interact with your database with Go. For details, see vertica-sql-go.

3.4 - Java

The Vertica JDBC driver provides you with a standard JDBC API.

The Vertica JDBC driver provides you with a standard JDBC API. If you have accessed other databases using JDBC, you should find accessing Vertica familiar. This section explains how to use the JDBC to connect your Java application to Vertica.

Prerequisites

You must install the JDBC client driver before creating Java client applications.

3.4.1 - JDBC feature support

The Vertica JDBC driver complies with the JDBC 4.0 standards (although it does not implement all of the optional features in them).

The Vertica JDBC driver complies with the JDBC 4.0 standards (although it does not implement all of the optional features in them). Your application can use the DatabaseMetaData class to determine if the driver supports a particular feature it wants to use. In addition, the driver implements the Wrapper interface, which lets your client code discover Vertica-specific extensions to the JDBC standard classes, such as VerticaConnection and VerticaStatement classes.

Some important facts to keep in mind when using the Vertica JDBC driver:

  • Cursors are forward only and are not scrollable. Result sets cannot be updated.

  • A connection supports executing a single statement at any time. If you want to execute multiple statements simultaneously, you must open multiple connections.

  • CallableStatement is supported as of the version 12.0.0 of the client driver.

Multiple SQL statement support

The Vertica JDBC driver can execute strings containing multiple statements. For example:

stmt.executeUpdate("CREATE TABLE t(a INT);INSERT INTO t VALUES(10);");

Only the Statement interface supports executing strings containing multiple SQL statements. You cannot use multiple statement strings with PreparedStatement. COPY statements that copy a file from a host file system work in a multiple statement string. However, client COPY statements (COPY FROM STDIN) do not work.

Multiple batch conversion to COPY statements

The Vertica JDBC driver converts all batch inserts into Vertica COPY statements. If you turn off your JDBC connection's AutoCommit property, the JDBC driver uses a single COPY statement to load data from sequential batch inserts which can improve load performance by reducing overhead. See Batch inserts using JDBC prepared statements for details.

JDBC version

The version of JDBC is determined by the version of the JVM. A JVM version of 8 or higher uses JDBC 4.2.

Multiple active result sets (MARS)

The Vertica JDBC driver supports Multiple active result sets (MARS). MARS allows the execution of multiple queries on a single connection. While ResultBufferSize sends the results of a query directly to the client, MARS stores the results first on the server. Once query execution has finished and all of the results have been stored, you can make a retrieval request to the server to have rows returned to the client.

3.4.2 - Creating and configuring a connection

Before your Java application can interact with Vertica, it must create a connection.

Before your Java application can interact with Vertica, it must create a connection. Connecting to Vertica using JDBC is similar to connecting to most other databases.

Importing SQL packages

Before creating a connection, you must import the Java SQL packages. A simple way to do so is to import the entire package using a wildcard:

import java.sql.*;

You may also want to import the Properties class. You can use an instance of this class to pass connection properties when instantiating a connection, rather than encoding everything within the connection string:

import java.util.Properties;

Applications can run in a Java 6 or later JVM. If so, then the JVM automatically loads the Vertica JDBC 4.0-compatible driver without requiring the call to Class.forName. However, making this call does not adversely affect the process. Thus, if you want your application to be compatible with both Java 5 and Java 6 (or later) JVMs, it can still call Class.forName.

Opening the connection

With SQL packages imported, you are ready to create your connection by calling the DriverManager.getConnection() method. You supply this method with at least the following information:

  • The IP address or host name of a node in the database cluster.

    You can provide an IPv4 address, IPv6 address, or host name.

    In mixed IPv4/IPv6 networks, the DNS server configuration determines which IP version address is sent first. Use the PreferredAddressFamily option to force the connection to use either IPv4 or IPv6.

  • Port number for the database

  • Username of a database user account

  • Password of the user (if the user has a password)

The first three parameters are always supplied as part of the connection string, a URL that tells the JDBC driver where to find the database. The format of the connection string is (/databaseName is optional):

jdbc:vertica://VerticaHost:portNumber/databaseName

The first portion of the connection string selects the Vertica JDBC driver, followed by the location of the database.

You can provide the last two parameters, username and password, to the JDBC driver, in one of three ways:

  • As part of the connection string. The parameters are encoded similarly to URL parameters:

    "jdbc:vertica://VerticaHost:portNumber/databaseName?user=username&password=password"
    
  • As separate parameters to DriverManager.getConnection():

    Connection conn = DriverManager.getConnection(
            "jdbc:vertica://VerticaHost:portNumber/databaseName",
            "username", "password");
    
  • In a Properties object:

    Properties myProp = new Properties();
    myProp.put("user", "username");
    myProp.put("password", "password");
    Connection conn = .getConnection(
        "jdbc:vertica://VerticaHost:portNumber/databaseName", myProp);
    

Of these three methods, the Properties object is the most flexible because it makes passing additional connection properties to the getConnection() method easy. See Connection Properties and Setting and getting connection property values for more information about the additional connection properties.

If there is any problem establishing a connection to the database, the getConnection() method throws a SQLException on one of its subclasses. To prevent an exception, enclose the method within a try-catch block, as shown in the following complete example of establishing a connection.

import java.sql.*;
import java.util.Properties;

public class VerySimpleVerticaJDBCExample {
    public static void main(String[] args) {
        /*
         * If your client needs to run under a Java 5 JVM, It will use the older
         * JDBC 3.0-compliant driver, which requires you manually load the
         * driver using Class.forname
         */
        /*
         * try { Class.forName("com.vertica.jdbc.Driver"); } catch
         * (ClassNotFoundException e) { // Could not find the driver class.
         * Likely an issue // with finding the .jar file.
         * System.err.println("Could not find the JDBC driver class.");
         * e.printStackTrace(); return; // Bail out. We cannot do anything
         * further. }
         */
        Properties myProp = new Properties();
        myProp.put("user", "dbadmin");
        myProp.put("password", "vertica");
        myProp.put("loginTimeout", "35");
        myProp.put("KeystorePath", "c:/keystore/keystore.jks");
     myProp.put("KeystorePassword", "keypwd");
     myProp.put("TrustStorePath", "c:/truststore/localstore.jks");
     myProp.put("TrustStorePassword", "trustpwd");
        Connection conn;
        try {
            conn = DriverManager.getConnection(
                    "jdbc:vertica://V_vmart_node0001.example.com:5433/vmart", myProp);
            System.out.println("Connected!");
            conn.close();
        } catch (SQLTransientConnectionException connException) {
            // There was a potentially temporary network error
            // Could automatically retry a number of times here, but
            // instead just report error and exit.
            System.out.print("Network connection issue: ");
            System.out.print(connException.getMessage());
            System.out.println(" Try again later!");
            return;
        } catch (SQLInvalidAuthorizationSpecException authException) {
            // Either the username or password was wrong
            System.out.print("Could not log into database: ");
            System.out.print(authException.getMessage());
            System.out.println(" Check the login credentials and try again.");
            return;
        } catch (SQLException e) {
            // Catch-all for other exceptions
            e.printStackTrace();
        }
    }
}

Creating a connection with a keystore and truststore

You can create secure connections with your JDBC client driver using a keystore and a truststore. For more information on security within Vertica, refer to Security and authentication.

For examples and instructions on how to generate (or import external) certificates in Vertica, see Generating TLS certificates and keys.

To view your keys and certificates in Vertica, see CERTIFICATES and CRYPTOGRAPHIC_KEYS.

  1. Generate your own self-signed certificate or use an existing CA (certificate authority) certificate as the root CA. For information on this process, refer to the Schannel documentation.

  2. Optional: Generate or import an intermediate CA certificate signed by your root CA. While not required, having an intermediate CA can be useful for testing and debugging your connection.

  3. Generate and sign (or import) a server certificate for Vertica.

  4. Use ALTER TLS CONFIGURATION to configure Vertica to use client/server TLS for new connections. For more information, see Configuring client-server TLS.

    For Server Mode (no client-certificate verification):

    => ALTER TLS CONFIGURATION server TLSMODE 'ENABLE';
    => ALTER TLS CONFIGURATION server CERTIFICATE server_cert;
    

    For Mutual Mode (client-certificate verification of varying strictness depending on the TLSMODE):

    => ALTER TLS CONFIGURATION server TLSMODE 'TRY_VERIFY';
    => ALTER TLS CONFIGURATION server CERTIFICATE server_cert ADD CA CERTIFICATES ca_cert;
    
  5. Optionally, you can disable all non-SSL connections with CREATE AUTHENTICATION.

    => CREATE AUTHENTICATION no_tls METHOD 'reject' HOST NO TLS '0.0.0.0/0';
    => CREATE AUTHENTICATION no_tls METHOD 'reject' HOST NO TLS '::/128';
    
  6. Generate and sign a certificate for your client using the same CA that signed your server certificate.

  7. Convert your chain of pem certificates to a single pkcs 12 file.

  8. Import the client key and chain into a keystore JKS file from your pkcs12 file. For information on using the keytool command interface, refer to the Java documentation.

    $ keytool -importkeystore -srckeystore -alias my_alias -srcstoretype PKCS12 -srcstorepass my_password -noprompt -deststorepass my_password -destkeypass my_password -destkeystore /tmp/keystore.jks
    
  9. Import the CA into a truststore JKS file.

    $ keytool -import -file certs/intermediate_ca.pem -alias my_alias -trustcacerts -keystore /tmp/truststore.jks -storepass my_truststore_password -noprompt
    

Usage considerations

  • When you disconnect a user session, any uncommitted transactions are automatically rolled back.

  • If your database is not compliant with your Vertica license terms, Vertica issues a SQLWarning when you establish the connection to the database. You can retrieve this warning using the Connection.getWarnings() method. See Managing licenses for more information about complying with your license terms.

3.4.2.1 - JDBC connection properties

You use connection properties to configure the connection between your JDBC client application and your Vertica database.

You use connection properties to configure the connection between your JDBC client application and your Vertica database. The properties provide the basic information about the connections, such as the server name and port number to use to connect to your database. They also let you tune the performance of your connection and enable logging.

You can set a connection property in one of the following ways:

  • Include the property name and value as part of the connection string you pass to the method DriverManager.getConnection().

  • Set the properties in a Properties object, and then pass it to the method DriverManager.getConnection().

  • Use the method VerticaConnection.setProperty(). With this approach, you can change only those connection properties that remain changeable after the connection has been established.

Also, some standard JDBC connection properties have getters and setters on the Connection interface, such as Connection.setAutoCommit().

Connection properties

The properties in the following table can only be set before you open the connection to the database. Two of them are required for every connection.

Property Description
BinaryTransfer

Boolean value that determines which mode Vertica uses when connecting to a JDBC client:

  • true: binary transfer (default)

  • false: text transfer

Binary transfer is generally more efficient at reading data from a server to a JDBC client and typically requires less bandwidth than text transfer. However, when transferring a large number of small values, binary transfer may use more bandwidth.

The data output by both modes is identical with the following exceptions for certain data types:

  • FLOAT: Binary transfer has slightly better precision.

  • TIMESTAMPTZ: Binary transfer can fail to get the session time zone and default to the local time zone, while text transfer reliably uses the session time zone.

  • NUMERIC: Binary transfer is forcibly disabled for NUMERIC data by the server for Vertica 11.0.2+.

ConnSettings A string containing SQL statements that the JDBC driver automatically runs after it connects to the database. You can use this property to set the locale or schema search path, or perform other configuration that the connection requires.
Label

Sets a label for the connection on the server. This value appears in the client_label column of the SESSIONS system table.

Default: jdbc-driver-version-random_number

SSL

When set to true, use SSL to encrypt the connection to the server. Vertica must be configured to handle SSL connections before you can establish an SSL-encrypted connection to it. See TLS protocol. This property has been deprecated in favor of the TLSmode property.

Default: false

TLSmode

TLSmode identifies the security level that Vertica applies to the JDBC connection. Vertica must be configured to handle TLS connections before you can establish an encrypted connection to it. See TLS protocol for details. Valid values are:

  • disable: JDBC connects using plain text and implements no security measures.

  • require: JDBC connects using TLS without verifying the CA certificate.

  • verify-ca: JDBC connects using TLS and confirms that the server certificate has been signed by the certificate authority. This setting is equivalent to the deprecated ssl=true property.

  • verify-full: JDBC connects using TLS, confirms that the server certificate has been signed by the certificate authority, and verifies that the host name matches the name provided in the server certificate.

If this property and the SSL property are set, this property takes precedence.

Default: disable

HostnameVerifier If TLSmode is set to verify-full, this property the fully qualified domain name of the verifier that you want to confirm the host name.
Password Required (for non-OAuth connections), the password to use to log into the database.
User Required (for non-OAuth connections), the database user name to use to connect to the database.
ConnectionLoadBalance

A Boolean value indicating whether the client is willing to have its connection redirected to another host in the Vertica database. This setting has an effect only if the server has also enabled connection load balancing. See About native connection load balancing for more information about native connection load balancing.

Default: false

BackupServerNode A string containing the host name or IP address of one or more hosts in the database. If the connection to the host specified in the connection string times out, the client attempts to connect to any host named in this string.The host name or IP address can also include a colon followed by the port number for the database. If no port number is specified, the client uses the standard port number ( 5433) . Separate multiple host name or IP address entries with commas.
PreferredAddressFamily

The IP version to use if the client and server have both IPv4 and IPv6 addresses and you have provided a host name, one of the following:

  • ipv4: Connect to the server using IPv4.

  • ipv6: Connect to the server using IPv6.

  • none: Use the IP address provided by the DNS server.

Default: none

KeyStorePath The path to a .JKS file containing your private keys and their corresponding certificate chains. For information on creating a keystore, refer to documentation for your development environment. For information on creating a keystore, refer to the Java documentation.
KeyStorePassword The password protecting the keystore file. If individual keys are also encrypted, the keystore file password must match the password for a key within the keystore.
TrustStorePath The path to a .JKS truststore file containing certificates from authorities you trust.
TrustStorePassword The password protecting the truststore file.
workload The name of the workload for the session. For details, see Workload routing.

OAuth connection properties

The following connection properties pertain to OAuth in JDBC.

Property Description
oauthaccesstoken Required if oauthrefreshtoken is unspecified, an OAuth token that authorizes a user to the database.
oauthrefreshtoken Required if oauthaccesstoken is unspecified, a token used to obtain a new access token when their old one expires.

Either OAuthAccessToken or OAuthRefreshToken must be set (programmatically or manually) to authenticate to Vertica with OAuth authentication.

You can omit both OAuthAccessToken and OAuthRefreshToken only if you authenticate to your identity provider directly with single sign-on through the client driver, which requires the machine running the ODBC driver to have access to a web browser.

For details on the different methods for retrieving access tokens, see Retrieving access tokens.

If you set this parameter, you must also set the OAuthClientSecret connection property.

In cases where introspection fails (e.g. when the access token expires), Vertica responds to the request with an error. If introspection fails and OAuthRefreshToken is specified, the driver attempts to refresh and silently retrieve a new access token. Otherwise, the driver passes error to the client application.

oauthclientsecret The secret provided by your identity provider for your client.
oauthtruststorepath The path to a custom truststore. If unspecified, JDBC uses the default system truststore.
oauthtruststorepassword The password to the truststore.

Timeout properties

With the following parameters, you can specify various timeouts for each step and the overall connection of JDBC to your Vertica database.

Property Description
LoginTimeout

The number of seconds Vertica waits for the client to log in to the database before throwing a SQLException.

Default: 0 (no timeout)

LoginNodeTimeout

The number of seconds the JDBC client waits before attempting to connect to the next node if the Vertica process is running, but does not respond. The "next" node is determined by the either the BackupServerNode connection property or DNS resolution. If you only provide a single IP address, the JDBC client returns an error.

A timeout value of 0 instructs JDBC to wait indefinitely for an error/a successful connection rather than attempt to connect to another node.

Default: 0 (no timeout)

LoginNetworkTimeout

The number of seconds the JDBC client has to establish a TCP connection to a Vertica node. A typical use case for this property is to let JDBC connect to another node if the system is down for maintenance and modifying the JDBC application's connection string is infeasible.

Default: 0 (no timeout)

NetworkTimeout

The number of milliseconds for the server to reply to a request after the client has established a connection with the database.

Default: 0

The relationship between these properties and the role they play when JDBC attempts to connect to a Vertica database is illustrated in the following diagram: A diagram how the timeouts behave when JDBC attempts to connect to a primary node and two backup nodes

General properties

The following properties can be set after the connection is established. None of these properties are required.

Property Description
AutoCommit

Controls whether the connection automatically commits transactions. Set this parameter to false to prevent the connection from automatically committing its transactions. You often want to do this when you are bulk loading multiple batches of data and you want the ability to roll back all of the loads if an error occurs.

Set After Connection: Connection.setAutoCommit()

Default: true

DirectBatchInsert Deprecated, always set to true.
DisableCopyLocal

When set to true, disables file-based COPY LOCAL operations, including copying data from local files and using local files to store data and exceptions. You can use this property to prevent users from writing to and copying from files on a Vertica host, including an MC host.

Default: false

MultipleActiveResultSets

Allows more than one active result set on a single connection via MultipleActiveResultSets (MARS).

If both MultipleActiveResultSets and ResultBufferSize are turned on, MultipleActiveResultSets takes precedence. The connection does not provide an error, however ResultBufferSize is ignored.

Set After Connection: VerticaConnection.setProperty()

Default: false

ReadOnly

When set to true, makes the data connection read-only. Any queries attempting to update the database using a read-only connection cause a SQLException.

Set After Connection: Connection.setReadOnly()

Default: false

ResultBufferSize

Sets the size of the buffer the Vertica JDBC driver uses to temporarily store result sets. A value of 0 means ResultBufferSize is turned off.

Note: This property was named maxLRSMemory in previous versions of the Vertica JDBC driver.

Set After Connection: VerticaConnection.setProperty()

Default: 8912 (8KB)

SearchPath

Sets the schema search path for the connection. This value is a string containing a comma-separated list of schema names. See Setting Search Paths for more information on the schema search path.

Set After Connection: VerticaConnection.setProperty()

Default: "$user", public, v_catalog, v_monitor, v_internal

ThreePartNaming

A Boolean value that controls how DatabaseMetaData reports the catalog name. When set to true, the database name is returned as the catalog name in the database metadata. When set to false, NULL is returned as the catalog name.

Enable this option if your client software is set up to get the catalog name from the database metadata for use in a three-part name reference.

Set After Connection: VerticaConnection.setProperty()

Default: true

TransactionIsolation

Sets the isolation level of the transactions that use the connection. See Changing the transaction isolation level for details.

Note: In previous versions of the Vertica JDBC driver, this property was only available using a getter and setter on the PGConnection object. You can now set it in the same way as other connection properties.

Set After Connection: Connection.setTransactionIsolation()

Default: TRANSACTION_READ_COMMITTED

Logging properties

The properties that control client logging must be set before the connection is opened. None of these properties are required, and none can be changed after the Connection object has been instantiated.

Property Description
LogLevel

Sets the type of information logged by the JDBC driver. The value is set to one of the following values:

  • "DEBUG"

  • "ERROR"

  • "TRACE"

  • "WARNING"

  • "INFO"

  • "OFF"

Default: "OFF"

LogNameSpace

Restricts logging to just messages generated by a specific packages. Valid values are:

  • com.vertica — All messages generated by the JDBC driver

  • com.vertica.jdbc — All messages generated by the top-level JDBC API

  • com.vertica.jdbc.kv — A ll messages generated by the JDBC KV API)

  • com.vertica.jdbc.core — Connection and statement settings

  • com.vertica.jdbc.io — Client/server protocol messages

  • com.vertica.jdbc.util — Miscellaneous utilities

  • com.vertica.jdbc.dataengine — Query execution and result set iteration

  • com.vertica.dataengine — Query execution and result set iteration

LogPath

The path for the log file.

Default: The current working directory

Kerberos connection parameters

Use the following parameters to set the service and host name principals for client authentication using Kerberos.

Parameters Description
JAASConfigName

Provides the name of the JAAS configuration that contains the JAAS Krb5LoginModule and its settings

Default: verticajdbc

KerberosServiceName

Provides the service name portion of the Vertica Kerberos principal, for example: vertichost@EXAMPLE.COM

Default: vertica

KerberosHostname

Provides the instance or host name portion of the Vertica Kerberos principal, for example: verticaosEXAMPLE.COM

Default: Value specified in the servername connection string property

Routable connection API connection parameters

Use the following parameters to set properties to enable and configure the connection for Routable Connection lookups.

Parameters Description
EnableRoutableQueries

Enables Routable Connection lookup. See Routing JDBC queries directly to a single node

Default: false

FailOnMultiNodePlans

If the query plan requires more than one node, then the query fails. Only applicable when EnableRoutableQueries = true.

Default: true

MetadataCacheLifetime

The time in seconds to keep projection metadata. Only applicable when EnableRoutableQueries = true.

Default:

MaxPooledConnections

Cluster-wide maximum number of connections to keep in the VerticaRoutableConnection’s internal pool. Only applicable when EnableRoutableQueries = true.

Default: 20

MaxPooledConnections
PerNode

Per-node maximum number of connections to keep in the VerticaRoutableConnection’s internal pool. Only applicable when EnableRoutableQueries = true.

Default: 5

For information about manipulating these attributes, see Setting and getting connection property values.

3.4.2.2 - Setting and getting connection property values

When creating a connection to Vertica, you can set connection properties by:.

You can set a connection property in one of the following ways:

  • Include the property name and value as part of the connection string you pass to the method DriverManager.getConnection().

  • Set the properties in a Properties object, and then pass it to the method DriverManager.getConnection().

  • Use the method VerticaConnection.setProperty(). With this approach, you can change only those connection properties that remain changeable after the connection has been established.

Also, some standard JDBC connection properties have getters and setters on the Connection interface, such as Connection.setAutoCommit().

Setting properties when connecting

When creating a connection to Vertica, you can set connection properties by:

  • Specifying them in the connection string.

  • Modifying the Properties object passed to getConnection().

Connection string properties

You can specify connection properties in the connection string with the same URL parameter format used for usernames and passwords. For example, the following string enables a TLS connection:

"jdbc:vertica://VerticaHost:5433/db?user=UserName&password=Password&TLSmode=require"

Setting a host name using the setProperty() method overrides the host name set in a connection string. If this occurs, Vertica might not be able to connect to a host. For example, using the connection string above, the following overrides the VerticaHost name:

Properties props = new Properties();
props.setProperty("dataSource", dataSourceURL);
props.setProperty("database", database);
props.setProperty("user", user);
props.setProperty("password", password);
ps.setProperty("jdbcDriver", jdbcDriver);
props.setProperty("hostName", "NonVertica_host");

However, if a new connection or override connection is needed, you can enter a valid host name in the hostname properties object.

The NonVertica_host hostname overrides VerticaHost name in the connection string. To avoid this issue, comment out the props.setProperty("hostName", "NonVertica_host");line:

//props.setProperty("hostName", "NonVertica_host");

Properties object

To set connection properties with the Properties object passed to the getConnection() call:

  1. Import the java.util.Properties class to instantiate a Properties object.

  2. Use the put() method to add name-value pairs to the object.

Properties myProp = new Properties();
myProp.put("user", "ExampleUser");
myProp.put("password", "password123");
myProp.put("LoginTimeout", "35");
Connection conn;
try {
    conn = DriverManager.getConnection(
        "jdbc:vertica://VerticaHost:/ExampleDB", myProp);
} catch (SQLException e) {
    e.printStackTrace();
}

Getting and setting properties after connecting

After you establish a connection with Vertica, you can use the VerticaConnection methods getProperty() and setProperty() to set the values of some connection properties, respectively.

The VerticaConnection.getProperty() method lets you get the value of some connection properties. Use this method to change the value for properties that can be set after you establish a connection with Vertica.

Because these methods are Vertica-specific, you must cast your Connection object to the VerticaConnection interface with one of the following methods:

  • Import the Connection object into your client application.

  • Use a fully-qualified reference: com.vertica.jdbc.VerticaConnection.

The following example demonstrates getting and setting the value of the ReadOnly property.

import java.sql.*;
import java.util.Properties;
import com.vertica.jdbc.*;

public class SetConnectionProperties {
    public static void main(String[] args) {
        // Note: If your application needs to run under Java 5, you need to
        // load the JDBC driver using Class.forName() here.
        Properties myProp = new Properties();
        myProp.put("user", "ExampleUser");
        myProp.put("password", "password123");
        // Set ReadOnly to true initially
        myProp.put("ReadOnly", "true");
        Connection conn;
        try {
            conn = DriverManager.getConnection(
                            "jdbc:vertica://VerticaHost:5433/ExampleDB",
                            myProp);
            // Show state of the ReadOnly property. This was set at the
            // time the connection was created.
            System.out.println("ReadOnly state: "
                            + ((VerticaConnection) conn).getProperty(
                                            "ReadOnly"));

            // Change it and show it again
            ((VerticaConnection) conn).setProperty("ReadOnly", false);
            System.out.println("ReadOnly state is now: " +
                             ((VerticaConnection) conn).getProperty(
                                             "ReadOnly"));
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

When run, the example prints the following on the standard output:

ReadOnly state: true
ReadOnly state is now: false

3.4.2.3 - Configuring TLS for JDBC clients

To configure TLS for JDBC clients:.

To configure TLS for JDBC clients:

Setting keystore/truststore properties

You can set the keystore and truststore properties in the following ways, each with their own pros and cons:

  • At the driver level.

  • At the JVM level.

Driver-level configuration

If you use tools like DbVizualizer with many connections, configure the keystore and truststore with the JDBC connection properties. This does, however, expose these values in the connection string:

  • KeyStorePath

  • KeyStorePassword

  • TrustStorePath

  • TrustStorePassword

For example:

Properties props = new Properties();
props.setProperty("KeyStorePath", keystorepath);
props.setProperty("KeyStorePassword", keystorepassword);
props.setProperty("TrustStorePath", truststorepath);
props.setProperty("TrustStorePassword", truststorepassword);

JVM-level configuration

Setting keystore and truststore parameters at the JVM level excludes them from the connection string, which may be more accommodating for environments with more stringent security requirements:

  • javax.net.ssl.keyStore

  • javax.net.ssl.trustStore

  • javax.net.ssl.keyStorePassword

  • javax.net.ssl.trustStorePassword

For example:

System.setProperty("javax.net.ssl.keyStore","clientKeyStore.key");
System.setProperty("javax.net.ssl.trustStore","clientTrustStore.key");
System.setProperty("javax.net.ssl.keyStorePassword","new_keystore_password")
System.setProperty("javax.net.ssl.trustStorePassword","new_truststore_password");

Set the TLSmode connection property

You can set the TLSmode connection property to determine how certificates are handled. TLSmode is disabled by default.

TLSmode identifies the security level that Vertica applies to the JDBC connection. Vertica must be configured to handle TLS connections before you can establish an encrypted connection to it. See TLS protocol for details. Valid values are:

  • disable: JDBC connects using plain text and implements no security measures.

  • require: JDBC connects using TLS without verifying the CA certificate.

  • verify-ca: JDBC connects using TLS and confirms that the server certificate has been signed by the certificate authority. This setting is equivalent to the deprecated ssl=true property.

  • verify-full: JDBC connects using TLS, confirms that the server certificate has been signed by the certificate authority, and verifies that the host name matches the name provided in the server certificate.

If this property and the SSL property are set, this property takes precedence.

For example, to configure JDBC to connect to the server with TLS without verifying the CA certificate, you can set the TLSmode property to 'require' with the method VerticaConnection.setProperty():

Properties props = new Properties();
props.setProperty("TLSmode", "verify-full");

Run the SSL debug utility

After configuring TLS, you can run the following for a debugging utility:

$ java -Djavax.net.debug=ssl

You can use several debug specifiers (options) with the debug utility. The specifiers help narrow the scope of the debugging information that is returned. For example, you could specify one of the options that prints handshake messages or session activity.

For information on the debug utility and its options, see Debugging Utilities in the Oracle document, JSSE Reference Guide.

For information on interpreting debug information, refer to the Oracle document, Debugging SSL/TLS Connections.

3.4.2.4 - Setting and returning a client connection label

The JDBC Client has a method to set and return the client connection label: getClientInfo() and setClientInfo(). You can use these methods with the SQL Functions GET_CLIENT_LABEL and SET_CLIENT_LABEL.

When you use these two methods, make sure you pass the string value APPLICATIONNAME to both the setter and getter methods.

Use setClientInfo() to create a client label, and use getClientInfo() to return the client label:

import java.sql.*;
import java.util.Properties;

public class ClientLabelJDBC {

    public static void main(String[] args) {
        Properties myProp = new Properties();
        myProp.put("user", "dbadmin");
        myProp.put("password", "");
        myProp.put("loginTimeout", "35");
        Connection conn;
        try {
            conn = DriverManager.getConnection(
                    "jdbc:vertica://example.com:5433/mydb", myProp);
            System.out.println("Connected!");
            conn.setClientInfo("APPLICATIONNAME", "JDBC Client - Data Load");
            System.out.println("New Conn label: " + conn.getClientInfo("APPLICATIONNAME"));
            conn.close();
        } catch (SQLTransientConnectionException connException) {
            // There was a potentially temporary network error
            // Could automatically retry a number of times here, but
            // instead just report error and exit.
            System.out.print("Network connection issue: ");
            System.out.print(connException.getMessage());
            System.out.println(" Try again later!");
            return;
        } catch (SQLInvalidAuthorizationSpecException authException) {
            // Either the username or password was wrong
            System.out.print("Could not log into database: ");
            System.out.print(authException.getMessage());
            System.out.println(" Check the login credentials and try again.");
            return;
        } catch (SQLException e) {
            // Catch-all for other exceptions
            e.printStackTrace();
        }
    }
}

When you run this method, it prints the following result to the standard output:

Connected!
New Conn Label: JDBC Client - Data Load

3.4.2.5 - Setting the locale for JDBC sessions

You set the locale for a connection while opening it by including a SET LOCALE statement in the ConnSettings property, or by executing a SET LOCALE statement at any time after opening the connection.

You set the locale for a connection while opening it by including a SET LOCALE statement in the ConnSettings property, or by executing a SET LOCALE statement at any time after opening the connection. Changing the locale of a Connection object affects all of the Statement objects you instantiated using it.

You can get the locale by executing a SHOW LOCALE query. The following example demonstrates setting the locale using ConnSettings and executing a statement, as well as getting the locale:

import java.sql.*;
import java.util.Properties;

public class GetAndSetLocale {
    public static void main(String[] args) {

     // If running under a Java 5 JVM, you need to load the JDBC driver
     // using Class.forname here

     Properties myProp = new Properties();
        myProp.put("user", "ExampleUser");
        myProp.put("password", "password123");

        // Set Locale to true en_GB on connection. After the connection
        // is established, the JDBC driver runs the statements in the
        // ConnSettings property.
        myProp.put("ConnSettings", "SET LOCALE TO en_GB");
        Connection conn;
        try {
            conn = DriverManager.getConnection(
                            "jdbc:vertica://VerticaHost:5433/ExampleDB",
                            myProp);

            // Execute a query to get the locale. The results should
            // show "en_GB" as the locale, since it was set by the
            // conn settings property.
            Statement stmt = conn.createStatement();
            ResultSet rs = null;
            rs = stmt.executeQuery("SHOW LOCALE");
            System.out.print("Query reports that Locale is set to: ");
            while (rs.next()) {
                System.out.println(rs.getString(2).trim());
            }

            // Now execute a query to set locale.
            stmt.execute("SET LOCALE TO en_US");

            // Run query again to get locale.
            rs = stmt.executeQuery("SHOW LOCALE");
            System.out.print("Query now reports that Locale is set to: ");
            while (rs.next()) {
                System.out.println(rs.getString(2).trim());
            }
            // Clean up
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

Running the above example displays the following on the system console:

Query reports that Locale is set to: en_GB (LEN)
Query now reports that Locale is set to: en_US (LEN)

Notes:

  • JDBC applications use a UTF-16 character set encoding and are responsible for converting any non-UTF-16 encoded data to UTF-16. Failing to convert the data can result in errors or the data being stored incorrectly.

  • The JDBC driver converts UTF-16 data to UTF-8 when passing to the Vertica server and converts data sent by Vertica server from UTF-8 to UTF-16 .

3.4.2.6 - Changing the transaction isolation level

Changing the transaction isolation level lets you choose how transactions prevent interference from other transactions.

Changing the transaction isolation level lets you choose how transactions prevent interference from other transactions. By default, the JDBC driver matches the transaction isolation level of the Vertica server. The Vertica default transaction isolation level is READ_COMMITTED, which means any changes made by a transaction cannot be read by any other transaction until after they are committed. This prevents a transaction from reading data inserted by another transaction that is later rolled back.

Vertica also supports the SERIALIZABLE transaction isolation level. This level locks tables to prevent queries from having the results of their WHERE clauses changed by other transactions. Locking tables can have a performance impact, since only one transaction is able to access the table at a time.

A transaction retains its isolation level until it completes, even if the session's isolation level changes during the transaction. Vertica internal processes (such as the Tuple Mover and refresh operations) and DDL operations always run at the SERIALIZABLE isolation level to ensure consistency.

You can change the transaction isolation level connection property after the connection has been established using the Connection object's setter (setTransactionIsolation()) and getter (getTransactionIsolation()). The value for transaction isolation property is an integer. The Connection interface defines constants to help you set the value in a more intuitive manner:

Constant Value
Connection.TRANSACTION_READ_COMMITTED 2
Connection.TRANSACTION_SERIALIZABLE 8

The following example demonstrates setting the transaction isolation level to SERIALIZABLE.

import java.sql.*;
import java.util.Properties;

public class SetTransactionIsolation {
    public static void main(String[] args) {
        Properties myProp = new Properties();
        myProp.put("user", "ExampleUser");
        myProp.put("password", "password123");
        Connection conn;
        try {
            conn = DriverManager.getConnection(
                            "jdbc:vertica://VerticaHost:5433/ExampleDB",
                            myProp);
            // Get default transaction isolation
            System.out.println("Transaction Isolation Level: "
                            + conn.getTransactionIsolation());
            // Set transaction isolation to SERIALIZABLE
            conn.setTransactionIsolation(Connection.TRANSACTION_SERIALIZABLE);
            // Get the transaction isolation again
            System.out.println("Transaction Isolation Level: "
                            + conn.getTransactionIsolation());
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

Running the example results in the following being printed out to the console:

Transaction Isolation Level: 2Transaction Isolation Level: 8

3.4.2.7 - JDBC connection pools

A pooling data source uses a collection of persistent connections in order to reduce the overhead of repeatedly opening network connections between the client and server.

A pooling data source uses a collection of persistent connections in order to reduce the overhead of repeatedly opening network connections between the client and server. Opening a new connection for each request is more costly for both the server and the client than keeping a small pool of connections open constantly, ready to be used by new requests. When a request comes in, one of the pre-existing connections in the pool is assigned to it. Only if there are no free connections in the pool is a new connection created. Once the request is complete, the connection returns to the pool and waits to service another request.

The Vertica JDBC driver supports connection pooling as defined in the JDBC 4.0 standard. If you are using a J2EE-based application server in conjunction with Vertica, it should already have a built-in data pooling feature. All that is required is that the application server work with the PooledConnection interface implemented by Vertica's JDBC driver. An application server's pooling feature is usually well-tuned for the works loads that the server is designed to handle. See your application server's documentation for details on how to work with pooled connections. Normally, using pooled connections should be transparent in your code—you will just open connections and the application server will worry about the details of pooling them.

If you are not using an application server, or your application server does not offer connection pooling that is compatible with Vertica, you can use a third-party pooling library, such as the open-source c3p0 or DBCP libraries, to implement connection pooling.

3.4.2.8 - Load balancing in JDBC

To enable native load balancing on your client, set the ConnectionLoadBalance connection parameter to true.

Native connection load balancing

Native connection load balancing helps spread the overhead caused by client connections on the hosts in the Vertica database. Both the server and the client must enable native connection load balancing. If enabled by both, then when the client initially connects to a host in the database, the host picks a host to handle the client connection from a list of the currently up hosts in the database, and informs the client which host it has chosen.

If the initially-contacted host does not choose itself to handle the connection, the client disconnects, then opens a second connection to the host selected by the first host. The connection process to this second host proceeds as usual—if SSL is enabled, then SSL negotiations begin, otherwise the client begins the authentication process. See About native connection load balancing for details.

To enable native load balancing on your client, set the ConnectionLoadBalance connection parameter to true. The following example demonstrates:

  • Connecting to the database several times with native connection load balancing enabled.

  • Fetching the name of the node handling the connection from the V_MONITOR.CURRENT_SESSION system table.


import java.sql.*;
import java.util.Properties;
import java.sql.*;
import java.util.Properties;

public class JDBCLoadingBalanceExample {
    public static void main(String[] args) {
        Properties myProp = new Properties();
        myProp.put("user", "dbadmin");
        myProp.put("password", "example_password123");
        myProp.put("loginTimeout", "35");
        myProp.put("ConnectionLoadBalance", "1");
        Connection conn;

        for (int x = 1; x <= 4; x++) {
            try {
                System.out.print("Connect attempt #" + x + "...");
                conn = DriverManager.getConnection(
                    "jdbc:vertica://node01.example.com:5433/vmart", myProp);
                Statement stmt = conn.createStatement();
                // Set the load balance policy to round robin before testing the database's load balancing.
                stmt.execute("SELECT SET_LOAD_BALANCE_POLICY('ROUNDROBIN');");
                // Query system to table to see what node we are connected to. Assume a single row
                // in response set.
                ResultSet rs = stmt.executeQuery("SELECT node_name FROM v_monitor.current_session;");
                rs.next();
                System.out.println("Connected to node " + rs.getString(1).trim());
                conn.close();
            } catch (SQLTransientConnectionException connException) {
                // There was a potentially temporary network error
                // Could automatically retry a number of times here, but
                // instead just report error and exit.
                System.out.print("Network connection issue: ");
                System.out.print(connException.getMessage());
                System.out.println(" Try again later!");
                return;
            } catch (SQLInvalidAuthorizationSpecException authException) {
                // Either the username or password was wrong
                System.out.print("Could not log into database: ");
                System.out.print(authException.getMessage());
                System.out.println(" Check the login credentials and try again.");
                return;
            } catch (SQLException e) {
                // Catch-all for other exceptions
                e.printStackTrace();
            }
        }
    }
}

Running the previous example produces the following output:


Connect attempt #1...Connected to node v_vmart_node0002
Connect attempt #2...Connected to node v_vmart_node0003
Connect attempt #3...Connected to node v_vmart_node0001
Connect attempt #4...Connected to node v_vmart_node0002

Hostname-based load balancing

You can load balance workloads by resolving a single hostname to multiple IP addresses. When you specify the hostname for the DriverManager.getConnection() method, the hostname resolves to a random listed IP address from the each connection.

For example, the hostname verticahost.example.com has the following entries in etc/hosts:

192.0.2.0 verticahost.example.com
192.0.2.1 verticahost.example.com
192.0.2.2 verticahost.example.com

Specifying verticahost.example.com as the connection for DriverManager.getConnection() randomly resolves to one of the listed IP address.

3.4.2.9 - JDBC connection failover

When run, the example outputs output similar to the following on the system console:.

If a client application attempts to connect to a host in the Vertica cluster that is down, the connection attempt fails when using the default connection configuration. This failure usually returns an error to the user. The user must either wait until the host recovers and retry the connection or manually edit the connection settings to choose another host.

Due to Vertica Analytic Database's distributed architecture, you usually do not care which database host handles a client application's connection. You can use the client driver's connection failover feature to prevent the user from getting connection errors when the host specified in the connection settings is unreachable. The JDBC driver gives you several ways to let the client driver automatically attempt to connect to a different host if the one specified in the connection parameters is unreachable:

  • Configure your DNS server to return multiple IP addresses for a host name. When you use this host name in the connection settings, the client attempts to connect to the first IP address from the DNS lookup. If the host at that IP address is unreachable, the client tries to connect to the second IP, and so on until it either manages to connect to a host or it runs out of IP addresses.

  • Supply a list of backup hosts for the client driver to try if the primary host you specify in the connection parameters is unreachable.

  • (JDBC only) Use driver-specific connection properties to manage timeouts before attempting to connect to the next node.

For all methods, the process of failover is transparent to the client application (other than specifying the list of backup hosts, if you choose to use the list method of failover). If the primary host is unreachable, the client driver automatically tries to connect to other hosts.

Failover only applies to the initial establishment of the client connection. If the connection breaks, the driver does not automatically try to reconnect to another host in the database.

Choosing a failover method

You usually choose to use one of the two failover methods. However, they do work together. If your DNS server returns multiple IP addresses and you supply a list of backup hosts, the client first tries all of the IPs returned by the DNS server, then the hosts in the backup list.

The DNS method of failover centralizes the configuration client failover. As you add new nodes to your Vertica Analytic Database cluster, you can choose to add them to the failover list by editing the DNS server settings. All client systems that use the DNS server to connect to Vertica Analytic Database automatically use connection failover without having to change any settings. However, this method does require administrative access to the DNS server that all clients use to connect to the Vertica Analytic Database cluster. This may not be possible in your organization.

Using the backup server list is easier than editing the DNS server settings. However, it decentralizes the failover feature. You may need to update the application settings on each client system if you make changes to your Vertica Analytic Database cluster.

Using DNS failover

To use DNS failover, you need to change your DNS server's settings to map a single host name to multiple IP addresses of hosts in your Vertica Analytic Database cluster. You then have all client applications use this host name to connect to Vertica Analytic Database.

You can choose to have your DNS server return as many IP addresses for the host name as you want. In smaller clusters, you may choose to have it return the IP addresses of all of the hosts in your cluster. However, for larger clusters, you should consider choosing a subset of the hosts to return. Otherwise there can be a long delay as the client driver tries unsuccessfully to connect to each host in a database that is down.

Using the backup host list

To enable backup list-based connection failover, your client application has to specify at least one IP address or host name of a host in the BackupServerNode parameter. The host name or IP can optionally be followed by a colon and a port number. If not supplied, the driver defaults to the standard Vertica port number (5433). To list multiple hosts, separate them by a comma.

The following example demonstrates setting the BackupServerNode connection parameter to specify additional hosts for the connection attempt. The connection string intentionally has a non-existent node, so that the initial connection fails. The client driver has to resort to trying the backup hosts to establish a connection to Vertica.

import java.sql.*;
import java.util.Properties;

public class ConnectionFailoverExample {
    public static void main(String[] args) {
        // Assume using JDBC 4.0 driver on JVM 6+. No driver loading needed.
        Properties myProp = new Properties();
        myProp.put("user", "dbadmin");
        myProp.put("password", "vertica");
        // Set two backup hosts to be used if connecting to the first host
        // fails. All of these hosts will be tried in order until the connection
        // succeeds or all of the connections fail.
        myProp.put("BackupServerNode", "VerticaHost02,VerticaHost03");
        Connection conn;
        try {
            // The connection string is set to try to connect to a known
            // bad host (in this case, a host that never existed).
            // The database name is optional.
            conn = DriverManager.getConnection(
                    "jdbc:vertica://BadVerticaHost:5433/vmart", myProp);
            System.out.println("Connected!");
            // Query system to table to see what node we are connected to.
            // Assume a single row in response set.
            Statement stmt = conn.createStatement();
            ResultSet rs = stmt.executeQuery(
                    "SELECT node_name FROM v_monitor.current_session;");
            rs.next();
            System.out.println("Connected to node " + rs.getString(1).trim());
            // Done with connection.
            conn.close();
        } catch (SQLException e) {
            // Catch-all for other exceptions
            e.printStackTrace();
        }
    }
}

When run, the example outputs output similar to the following on the system console:

Connected!
Connected to node v_vmart_node0002

Notice that the connection was made to the first node in the backup list (node 2).

Specifying connection timeouts

LoginTimeout controls the timeout for JDBC to establish establish a TCP connection with a node and log in to Vertica.

LoginNodeTimeout controls the timeout for JDBC to log in to the Vertica database. After the specified timeout, JDBC attempts to connect to the "next" node, which is determined by either the connection property BackupServerNode or DNS resolution. This is useful if the node is up, but something is wrong with the Vertica process.

LoginNetworkTimeout controls the timeout for JDBC to establish a TCP connection to a Vertica node. If you do not set this connection property, if the node to which the JDBC client attempts to connect is down, the JDBC client will wait "indefinitely," but practically, the system default timeout of 70 seconds is used. A typical use case for LoginNetworkTimeout is to let JDBC connect to another node if the current Vertica node is down for maintenance and modifying the JDBC application's connection string is infeasible.

NetworkTimeout controls the timeout for Vertica to respond to a request from a client after it has established a connection and logged in to the database.

To set these parameters in a connection string:

# LoginTimeout is 30 seconds, LoginNodeTimeout is 10 seconds, LoginNetworkTimeout is 2 seconds, NetworkTimeout is 0.5 seconds
Connection conn = DriverManager.getConnection("jdbc:vertica://VerticaHost:5433/verticadb?user=dbadmin&loginTimeout=30&loginNodeTimeout=10"&loginNetworkTimeout=2&networkTimeout=500");

To set these parameters as a connection property:

Properties myProp = new Properties();
myProp.put("user", "dbadmin");
myProp.put("loginTimeout", "30"); // overall connection timeout is 30 seconds to make sure it is not too small for failover
myProp.put("loginNodeTimeout", "10"); // JDBC waits 10 seconds before attempting to connect to the next node if the Vertica process is running but does not respond
myProp.put("loginNetworkTimeout", "2"); // node connection timeout is 2 seconds
myProp.put("networkTimeout", "500"); // after the client has logged in, Vertica has 0.5 seconds to respond to each request
Connection conn = DriverManager.getConnection("jdbc:vertica://VerticaHost:5433/verticadb", myProp);

Interaction with load balancing

When native connection load balancing is enabled, the additional servers specified in the BackupServerNode connection parameter are only used for the initial connection to a Vertica host. If host redirects the client to another host in the database cluster to handle its connection request, the second connection does not use the backup node list. This is rarely an issue, since native connection load balancing is aware of which nodes are currently up in the database.

See Load balancing in JDBC for more information.

3.4.3 - JDBC data types

The JDBC driver transparently converts most Vertica data types to the appropriate Java data type.

The JDBC driver transparently converts most Vertica data types to the appropriate Java data type. In a few cases, a Vertica data type cannot be directly translated to a Java data type; these exceptions are explained in this section.

3.4.3.1 - The VerticaTypes class

JDBC does not support all of the data types that Vertica supports.

JDBC does not support all of the data types that Vertica supports. The Vertica JDBC client driver contains an additional class named VerticaTypes that helps you handle identifying these Vertica-specific data types. It contains constants that you can use in your code to specify Vertica data types. This class defines two different categories of data types:

  • Vertica's 13 types of interval values. This class contains constant properties for each of these types. You can use these constants to select a specific interval type when instantiating members of the VerticaDayTimeInterval and VerticaYearMonthInterval classes:

    // Create a day to second interval.
    VerticaDayTimeInterval dayInt = new VerticaDayTimeInterval(
            VerticaTypes.INTERVAL_DAY_TO_SECOND, 10, 0, 5, 40, 0, 0, false);
    // Create a year to month interval.
    VerticaYearMonthInterval monthInt = new VerticaYearMonthInterval(
            VerticaTypes.INTERVAL_YEAR_TO_MONTH, 10, 6, false);
    
  • Vertica UUID data type. One way you can use the VerticaTypes.UUID is to query a table's metadata to see if a column is a UUID. See UUID values for an example.

See the JDBC documentation for more information on this class.

3.4.3.2 - Numeric data alias conversion

The Vertica server supports data type aliases for integer, float and numeric types.

The Vertica server supports data type aliases for integer, float and numeric types. The JDBC driver reports these as its basic data types (BIGINT, DOUBLE PRECISION, and NUMERIC), as follows:

Vertica Server Types and Aliases Vertica JDBC Type

INTEGER

INT

INT8

BIGINT

SMALLINT

TINYINT

BIGINT

DOUBLE PRECISION

FLOAT5

FLOAT8

REAL

DOUBLE PRECISION

DECIMAL

NUMERIC

NUMBER

MONEY

NUMERIC

If a client application retrieves the values into smaller data types, Vertica JDBC driver does not check for overflows. The following example demonstrates the results of this overflow.

import java.sql.*;
import java.util.Properties;

public class JDBCDataTypes {
    public static void main(String[] args) {
        // If running under a Java 5 JVM, use you need to load the JDBC driver
        // using Class.forname here

        Properties myProp = new Properties();
        myProp.put("user", "ExampleUser");
        myProp.put("password", "password123");
        Connection conn;
        try {
            conn = DriverManager.getConnection(
                            "jdbc:vertica://VerticaHost:5433/VMart",
                             myProp);
            Statement statement = conn.createStatement();
            // Create a table that will hold a row of different types of
            // numeric data.
            statement.executeUpdate(
                    "DROP TABLE IF EXISTS test_all_types cascade");
            statement.executeUpdate("CREATE TABLE test_all_types ("
                            + "c0 INTEGER, c1 TINYINT, c2 DECIMAL, "
                            + "c3 MONEY, c4 DOUBLE PRECISION, c5 REAL)");
            // Add a row of values to it.
            statement.executeUpdate("INSERT INTO test_all_types VALUES("
                            + "111111111111, 444, 55555555555.5555, "
                            + "77777777.77,  88888888888888888.88, "
                            + "10101010.10101010101010)");
            // Query the new table to get the row back as a result set.
            ResultSet rs = statement
                            .executeQuery("SELECT * FROM test_all_types");
            // Get the metadata about the row, including its data type.
            ResultSetMetaData md = rs.getMetaData();
            // Loop should only run once...
            while (rs.next()) {
                // Print out the data type used to defined the column, followed
                // by the values retrieved using several different retrieval
                // methods.

                String[] vertTypes = new String[] {"INTEGER", "TINYINT",
                         "DECIMAL", "MONEY", "DOUBLE PRECISION", "REAL"};

                for (int x=1; x<7; x++) {
                    System.out.println("\n\nColumn " + x + " (" + vertTypes[x-1]
                            + ")");
                    System.out.println("\tgetColumnType()\t\t"
                            + md.getColumnType(x));
                    System.out.println("\tgetColumnTypeName()\t"
                            + md.getColumnTypeName(x));
                    System.out.println("\tgetShort()\t\t"
                            + rs.getShort(x));
                    System.out.println("\tgetLong()\t\t" + rs.getLong(x));
                    System.out.println("\tgetInt()\t\t" + rs.getInt(x));
                    System.out.println("\tgetByte()\t\t" + rs.getByte(x));
                }
            }
            rs.close();
            statement.executeUpdate("drop table test_all_types cascade");
            statement.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

The above example prints the following on the console when run:

Column 1 (INTEGER)
       getColumnType()        -5
    getColumnTypeName()    BIGINT
    getShort()        455
    getLong()        111111111111
    getInt()        -558038585
    getByte()        -57
Column 2 (TINYINT)
    getColumnType()        -5
    getColumnTypeName()    BIGINT
    getShort()        444
    getLong()        444
    getInt()        444
    getByte()        -68
Column 3 (DECIMAL)
    getColumnType()        2
    getColumnTypeName()    NUMERIC
    getShort()        -1
    getLong()        55555555555
    getInt()        2147483647
    getByte()        -1
Column 4 (MONEY)
    getColumnType()        2
    getColumnTypeName()    NUMERIC
    getShort()        -13455
    getLong()        77777777
    getInt()        77777777
    getByte()        113
Column 5 (DOUBLE PRECISION)
    getColumnType()        8
    getColumnTypeName()    DOUBLE PRECISION
    getShort()        -1
    getLong()        88888888888888900
    getInt()        2147483647
    getByte()        -1
Column 6 (REAL)
    getColumnType()        8
    getColumnTypeName()    DOUBLE PRECISION
    getShort()        8466
    getLong()        10101010
    getInt()        10101010
    getByte()        18

3.4.3.3 - Using intervals with JDBC

The JDBC standard does not contain a data type for intervals (the duration between two points in time).

The JDBC standard does not contain a data type for intervals (the duration between two points in time). To handle Vertica's INTERVAL data type, you must use JDBC's database-specific object type.

When reading an interval value from a result set, use the ResultSet.getObject() method to retrieve the value, and then cast it to one of the Vertica interval classes: VerticaDayTimeInterval (which represents all ten types of day/time intervals) or VerticaYearMonthInterval (which represents all three types of year/month intervals).

Using intervals in batch inserts

When inserting batches into tables that contain interval data, you must create instances of the VerticaDayTimeInterval or VerticaYearMonthInterval classes to hold the data you want to insert. You set values either when calling the class's constructor, or afterwards using setters. You then insert your interval values using the PreparedStatement.setObject() method. You can also use the .setString() method, passing it a string in "DD**HH:MM:SS" or "YY-MM" format.

The following example demonstrates inserting data into a table containing a day/time interval and a year/month interval:

import java.sql.*;
import java.util.Properties;
// You need to import the Vertica JDBC classes to be able to instantiate
// the interval classes.
import com.vertica.jdbc.*;

public class IntervalDemo {
    public static void main(String[] args) {
        // If running under a Java 5 JVM, use you need to load the JDBC driver
        // using Class.forname here
        Properties myProp = new Properties();
        myProp.put("user", "ExampleUser");
        myProp.put("password", "password123");
        Connection conn;
        try {
            conn = DriverManager.getConnection(
                    "jdbc:vertica://VerticaHost:5433/VMart", myProp);
            // Create table for interval values
            Statement stmt = conn.createStatement();
            stmt.execute("DROP TABLE IF EXISTS interval_demo");
            stmt.executeUpdate("CREATE TABLE interval_demo("
                    + "DayInt INTERVAL DAY TO SECOND, "
                    + "MonthInt INTERVAL YEAR TO MONTH)");
            // Insert data into interval columns using
            // VerticaDayTimeInterval and VerticaYearMonthInterval
            // classes.
            PreparedStatement pstmt = conn.prepareStatement(
                    "INSERT INTO interval_demo VALUES(?,?)");
            // Create instances of the Vertica classes that represent
            // intervals.
            VerticaDayTimeInterval dayInt = new VerticaDayTimeInterval(10, 0,
                    5, 40, 0, 0, false);
            VerticaYearMonthInterval monthInt = new VerticaYearMonthInterval(
                    10, 6, false);
            // These objects can also be manipulated using setters.
            dayInt.setHour(7);
            // Add the interval values to the batch
            ((VerticaPreparedStatement) pstmt).setObject(1, dayInt);
            ((VerticaPreparedStatement) pstmt).setObject(2, monthInt);
            pstmt.addBatch();
            // Set another row from strings.
            // Set day interval in "days HH:MM:SS" format
            pstmt.setString(1, "10 10:10:10");
            // Set year to month value in "MM-YY" format
            pstmt.setString(2, "12-09");
            pstmt.addBatch();
            // Execute the batch to insert the values.
            try {
                pstmt.executeBatch();
            } catch (SQLException e) {
                System.out.println("Error message: " + e.getMessage());
            }

Reading interval values

You read an interval value from a result set using the ResultSet.getObject() method, and cast the object to the appropriate Vertica object class: VerticaDayTimeInterval for day/time intervals or VerticaYearMonthInterval for year/month intervals. This is easy to do if you know that the column contains an interval, and you know what type of interval it is. If your application cannot assume the structure of the data in the result set it reads in, you can test whether a column contains a database-specific object type, and if so, determine whether the object belongs to either the VerticaDayTimeInterval or VerticaYearMonthInterval classes.

            // Retrieve the interval values inserted by previous demo.
            // Query the table to get the row back as a result set.
            ResultSet rs = stmt.executeQuery("SELECT * FROM interval_demo");
            // If you do not know the types of data contained in the result set,
            // you can read its metadata to determine the type, and use
            // additional information to determine the interval type.
            ResultSetMetaData md = rs.getMetaData();
            while (rs.next()) {
                for (int x = 1; x <= md.getColumnCount(); x++) {
                    // Get data type from metadata
                    int colDataType = md.getColumnType(x);
                    // You can get the type in a string:
                    System.out.println("Column " + x + " is a "
                            + md.getColumnTypeName(x));
                    // Normally, you'd have a switch statement here to
                    // handle all sorts of column types, but this example is
                    // simplified to just handle database-specific types
                    if (colDataType == Types.OTHER) {
                        // Column contains a database-specific type. Determine
                        // what type of interval it is. Assuming it is an
                        // interval...
                        Object columnVal = rs.getObject(x);
                        if (columnVal instanceof VerticaDayTimeInterval) {
                            // We know it is a date time interval
                            VerticaDayTimeInterval interval =
                                    (VerticaDayTimeInterval) columnVal;
                            // You can use the getters to access the interval's
                            // data
                            System.out.print("Column " + x + "'s value is ");
                            System.out.print(interval.getDay() + " Days ");
                            System.out.print(interval.getHour() + " Hours ");
                            System.out.println(interval.getMinute()
                                    + " Minutes");
                        } else if (columnVal instanceof VerticaYearMonthInterval) {
                            VerticaYearMonthInterval interval =
                                    (VerticaYearMonthInterval) columnVal;
                            System.out.print("Column " + x + "'s value is ");
                            System.out.print(interval.getYear() + " Years ");
                            System.out.println(interval.getMonth() + " Months");
                        } else {
                            System.out.println("Not an interval.");
                        }
                    }
                }
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

The example prints the following to the console:

Column 1 is a INTERVAL DAY TO SECOND
Column 1's value is 10 Days 7 Hours 5 Minutes
Column 2 is a INTERVAL YEAR TO MONTH
Column 2's value is 10 Years 6 Months
Column 1 is a INTERVAL DAY TO SECOND
Column 1's value is 10 Days 10 Hours 10 Minutes
Column 2 is a INTERVAL YEAR TO MONTH
Column 2's value is 12 Years 9 Months

Another option is to use database metadata to find columns that contain intervals.

// Determine the interval data types by examining the database
// metadata.
DatabaseMetaData dbmd = conn.getMetaData();
ResultSet dbMeta = dbmd.getColumns(null, null, "interval_demo", null);
int colcount = 0;
while (dbMeta.next()) {

    // Get the metadata type for a column.
    int javaType = dbMeta.getInt("DATA_TYPE");

    System.out.println("Column " + ++colcount + " Type name is " +
                    dbMeta.getString("TYPE_NAME"));

    if(javaType == Types.OTHER) {
      // The SQL_DATETIME_SUB column in the metadata tells you
      // Specifically which subtype of interval you have.
      // The VerticaDayTimeInterval.isDayTimeInterval()
      // methods tells you if that value is a day time.
      //
      int intervalType = dbMeta.getInt("SQL_DATETIME_SUB");
      if(VerticaDayTimeInterval.isDayTimeInterval(intervalType)) {
           // Now you know it is one of the 10 day/time interval types.
           // When you select this column you can cast to
           // VerticaDayTimeInterval.
           // You can get more specific by checking intervalType
           // against each of the 10 constants directly, but
           // they all are represented by the same object.
           System.out.println("column " + colcount + " is a " +
                           "VerticaDayTimeInterval intervalType = "
                          + intervalType);
      } else if(VerticaYearMonthInterval.isYearMonthInterval(
                      intervalType)) {
          //now you know it is one of the 3 year/month intervals,
          //and you can select the column and cast to
          // VerticaYearMonthInterval
          System.out.println("column " + colcount + " is a " +
                          "VerticaDayTimeInterval intervalType = "
                          + intervalType);
      } else {
          System.out.println("Not an interval type.");
      }
    }
}

3.4.3.4 - UUID values

UUID is a core data type in Vertica.

UUID is a core data type in Vertica. However, it is not a core Java data type. You must use the java.util.UUID class to represent UUID values in your Java code. The JDBC driver does not translate values from Vertica to non-core Java data types. Therefore, you must send UUID values to Vertica using generic object methods such as PreparedStatement.setObject(). You also use generic object methods (such as ResultSet.getObject()) to retrieve UUID values from Vertica. You then cast the retrieved objects as a member of the java.util.UUID class.

The following example code demonstrates inserting UUID values into and retrieving UUID values from Vertica.

package jdbc_uuid_example;

import java.sql.*;
import java.util.Properties;

public class VerticaUUIDExample {

    public static void main(String[] args) {

        Properties myProp = new Properties();
        myProp.put("user", "dbadmin");
        myProp.put("password", "");
        Connection conn;

        try {
            conn = DriverManager.getConnection("jdbc:vertica://doch01:5433/VMart",
                                                myProp);
            Statement stmt = conn.createStatement();

            // Create a table with a UUID column and a VARCHAR column.
            stmt.execute("DROP TABLE IF EXISTS UUID_TEST CASCADE;");
            stmt.execute("CREATE TABLE UUID_TEST (id UUID, description VARCHAR(25));");

            // Prepare a statement to insert a UUID and a string into the table.
            PreparedStatement ps = conn.prepareStatement("INSERT INTO UUID_TEST VALUES(?,?)");

            java.util.UUID uuid;  // Holds the UUID value.

            for (Integer x = 0; x < 10; x++) {
                // Generate a random uuid
                uuid = java.util.UUID.randomUUID();
                // Set the UUID value by calling setObject.
                ps.setObject(1, uuid);
                // Set the String value to indicate which UUID this is.
                ps.setString(2, "UUID #" + x);
                ps.execute();
            }

            // Query the uuid
            ResultSet rs = stmt.executeQuery("SELECT * FROM UUID_TEST ORDER BY description ASC");
            while (rs.next()) {
                // Cast the object from the result set as a UUID.
                uuid = (java.util.UUID) rs.getObject(1);
                System.out.println(rs.getString(2) + " : " +  uuid.toString());
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

The previous example prints output similar to the following:

UUID #0 : 67b6dcb6-c28c-4965-b9f7-5c830a04664d
UUID #1 : 485d3835-2887-4233-b003-392254fa97e0
UUID #2 : 81421f51-c803-473d-8cfc-2c184582a117
UUID #3 : bec8b86a-b650-47b0-852c-8229155332d9
UUID #4 : 8ae5e3ec-d143-4ef7-8901-24f6d0483abf
UUID #5 : 669696ce-5e86-4e87-b8d0-a937f5fc18d7
UUID #6 : 19609ec9-ec56-4444-9cfe-ad2b8de537dd
UUID #7 : 97182e1d-5c7e-4da1-9922-67e804fde173
UUID #8 : c76c3a2b-a9ef-4d65-b2fb-7c637f872b3c
UUID #9 : 3cbbcd26-c177-4277-b3df-bf4d9389f69d

Determining whether a column has a UUID data type

JDBC does not support the UUID data type. This limitation means you cannot use the usual ResultSetMetaData.getColumnType() method to determine column's data type is UUID. Calling this method on a UUID column returns Types.OTHER. This value is also to identify interval columns. You can use two ways to determine if a column contains UUIDs:

  • Use ResultSetMetaData.getColumnTypeName() to get the name of the column's data type. For UUID columns, this method returns the value "Uuid" as a String.

  • Query the table's metadata to get the SQL data type of the column. If this value is equal to VerticaTypes.UUID, the column's data type is UUID.

The following example demonstrates both of these techniques:

            // This example assumes you already have a database connection
            // and result set from a query on a table that may contain a UUID.

            //  Get the metadata of the result set to get the column definitions
            ResultSetMetaData meta = rs.getMetaData();
            int colcount;
            int maxcol = meta.getColumnCount();

            System.out.println("Using column metadata:");
            for (colcount = 1; colcount < maxcol; colcount++) {
            // .getColumnType() always returns "OTHER" for UUID columns.
                if (meta.getColumnType(colcount) == Types.OTHER) {
                    // To determine that it is a UUID column, test the name of the column type.
                    if (meta.getColumnTypeName(colcount).equalsIgnoreCase("uuid")) {
                        // It's a UUID column
                        System.out.println("Column "+ colcount + " is UUID");
                    }
                }
            }

            // You can also query the table's metadata to find its column types and compare
            // it to the VerticaType.UUID constant to see if it is a UUID column.
            System.out.println("Using table metadata:");
            DatabaseMetaData dbmd = conn.getMetaData();
            // Get the metdata for the previously-created test table.
            ResultSet tableMeta = dbmd.getColumns(null, null, "UUID_TEST", null);
            colcount = 0;
            // Each row in the result set has metadata that describes a single column.
            while (tableMeta.next()) {
                colcount++;
                // The SQL_DATA_TYPE column holds the Vertica database data type. You compare
                // this value to the VerticvaTypes.UUID constant to see if it is a UUID.
                if (tableMeta.getInt("SQL_DATA_TYPE") == VerticaTypes.UUID) {
                    // Column is a UUID data type...
                    System.out.println("Column " + colcount + " is a UUID column.");
                }
            }

This example prints the following to the console if it is run after running the prior example:

Using column metadata:
Column 1 is UUID
Using table metadata:
Column 1 is a UUID column.

3.4.3.5 - Complex types in JDBC

The results of a java.sql query are stored in a ResultSet.

The results of a java.sql query are stored in a ResultSet. If the ResultSet contains a column of complex type, you can retrieve it with one of the following:

  • For columns of type ARRAY, SET, or MAP, use getArray(), which returns a java.sql.Array.

  • For columns of type ROW, use getObject(), which returns a java.sql.Struct.

Type conversion table

The objects java.sql.Array and java.sql.Struct each have their own API for accessing complex type data. In each case, the data is returned as java.lang.Object and will need to be type cast to a Java type. The exact Java type to expect depends on the Vertica type used in the complex type definition, as shown in this type conversion table:

java.sql Type Vertica Type Java Type
BIT BOOL java.lang.Boolean
BIGINT INT java.lang.Long
DOUBLE FLOAT java.lang.Double
CHAR CHAR java.lang.String
VARCHAR VARCHAR java.lang.String
LONGVARCHAR LONGVARCHAR java.lang.String
DATE DATE java.sql.Date
TIME TIME java.sql.Time
TIME TIMETZ java.sql.Time
TIMESTAMP TIMESTAMP java.sql.Timestamp
TIMESTAMP TIMESTAMPTZ com.vertica.dsi.dataengine.utilities.TimestampTz
getIntervalRange(oid, typmod) INTERVAL com.vertica.jdbc.VerticaDayTimeInterval
getIntervalRange(oid, typmod) INTERVALYM com.vertica.jdbc.VerticaYearMonthInterval
BINARY BINARY byte[]
VARBINARY VARBINARY byte[]
LONGVARBINARY LONGVARBINARY byte[]
NUMERIC NUMERIC java.math.BigDecimal
TYPE_SQL_GUID UUID java.util.UUID
ARRAY ARRAY java.lang.Object[]
ARRAY SET java.lang.Object[]
STRUCT ROW java.sql.Struct
ARRAY MAP java.lang.Object[]

ARRAY, SET, and MAP columns

For example, the following methods run queries that return an ARRAY of some Vertica type, which is then type cast to an array of its corresponding Java type by the JDBC driver when retrieved with getArray(). This particular example starts with ARRAY[INT] and ARRAY[FLOAT], so they are type cast to Long[] and Double[], respectively, as determined by the type conversion table.

  • getArrayResultSetExample() shows how the ARRAY can be processed as a java.sql.ResultSet. This example uses getResultSet() which returns the underlying array as another ResultSet. You can use this underlying ResultSet to:

    • Retrieve the parent ResultSet.

    • Treat it as an Object array or ResultSet.

  • getArrayObjectExample() shows how the ARRAY can be processed as a native Java array. This example uses getArray() which returns the underlying array as an Object array rather than a ResultSet. This has the following implications:

    • You cannot use an underlying Object array to retrieve its parent array.

    • All underlying arrays are treated as Object arrays (rather than ResultSets.

package com.vertica.jdbc.test.samples;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.Array;
import java.sql.Struct;


public class ComplexTypesArraySamples
{
    /**
     * Executes a query and gets a java.sql.Array from the ResultSet. It then uses the Array#getResultSet
     * method to get a ResultSet containing the contents of the array.
     * @param conn A Connection to a Vertica database
     * @throws SQLException
     */
    public static void getArrayResultSetExample (Connection conn) throws SQLException {
        Statement stmt = conn.createStatement();

        final String queryText = "SELECT ARRAY[ARRAY[1,2,3],ARRAY[4,5,6],ARRAY[7,8,9]]::ARRAY[ARRAY[INT]] as array";
        final String targetColumnName = "array";

        System.out.println ("queryText: " + queryText);
        ResultSet rs = stmt.executeQuery(queryText);
        int targetColumnId = rs.findColumn (targetColumnName);

        while (rs.next ()) {
            Array currentSqlArray = rs.getArray (targetColumnId);
            ResultSet level1ResultSet = currentSqlArray.getResultSet();
            if (level1ResultSet != null) {
                while (level1ResultSet.next ()) {
                    // The first column of the result set holds the row index
                    int i = level1ResultSet.getInt(1) - 1;
                    Array level2SqlArray = level1ResultSet.getArray (2);
                    Object level2Object = level2SqlArray.getArray ();
                    // For this ARRAY[INT], the driver returns a Long[]
                    assert (level2Object instanceof Long[]);
                    Long [] level2Array = (Long [])level2Object;
                    System.out.println (" level1Object [" + i + "]: " + level2SqlArray.toString () + " (" + level2SqlArray.getClass() + ")");

                    for (int j = 0; j < level2Array.length; j++) {
                       System.out.println (" Value [" + i + ", " + j + "]: " + level2Array[j] + " (" + level2Array[j].getClass() + ")");
                   }
                }
            }
        }
    }

    /**
     * Executes a query and gets a java.sql.Array from the ResultSet. It then uses the Array#getArray
     * method to get the contents of the array as a Java Object [].
     * @param conn A Connection to a Vertica database
     * @throws SQLException
     */
    public static void getArrayObjectExample (Connection conn) throws SQLException {
        Statement stmt = conn.createStatement();

        final String queryText = "SELECT ARRAY[ARRAY[0.0,0.1,0.2],ARRAY[1.0,1.1,1.2],ARRAY[2.0,2.1,2.2]]::ARRAY[ARRAY[FLOAT]] as array";
        final String targetColumnName = "array";

        System.out.println ("queryText: " + queryText);
        ResultSet rs = stmt.executeQuery(queryText);
        int targetColumnId = rs.findColumn (targetColumnName);

        while (rs.next ()) {
            // Get the java.sql.Array from the result set
            Array currentSqlArray = rs.getArray (targetColumnId);
            // Get the internal Java Object implementing the array
            Object level1ArrayObject = currentSqlArray.getArray ();
            if (level1ArrayObject != null) {
                // All returned instances are Object[]
                assert (level1ArrayObject instanceof Object[]);
                Object [] level1Array = (Object [])level1ArrayObject;
                System.out.println ("Vertica driver returned a: " + level1Array.getClass());

                for (int i = 0; i < level1Array.length; i++) {
                    Object level2Object = level1Array[i];
                    // For this ARRAY[FLOAT], the driver returns a Double[]
                    assert (level2Object instanceof Double[]);
                    Double [] level2Array = (Double [])level2Object;
                    for (int j = 0; j < level2Array.length; j++) {
                         System.out.println (" Value [" + i + ", " + j + "]: " + level2Array[j] + " (" + level2Array[j].getClass() + ")");
                    }
                }
            }
        }
    }
}

The output of getArrayResultSetExample() shows that the Vertica column type ARRAY[INT] is type cast to Long[]:

queryText: SELECT ARRAY[ARRAY[1,2,3],ARRAY[4,5,6],ARRAY[7,8,9]]::ARRAY[ARRAY[INT]] as array
 level1Object [0]: [1,2,3] (class com.vertica.jdbc.jdbc42.S42Array)
 Value [0, 0]: 1 (class java.lang.Long)
 Value [0, 1]: 2 (class java.lang.Long)
 Value [0, 2]: 3 (class java.lang.Long)
 level1Object [1]: [4,5,6] (class com.vertica.jdbc.jdbc42.S42Array)
 Value [1, 0]: 4 (class java.lang.Long)
 Value [1, 1]: 5 (class java.lang.Long)
 Value [1, 2]: 6 (class java.lang.Long)
 level1Object [2]: [7,8,9] (class com.vertica.jdbc.jdbc42.S42Array)
 Value [2, 0]: 7 (class java.lang.Long)
 Value [2, 1]: 8 (class java.lang.Long)
 Value [2, 2]: 9 (class java.lang.Long)

The output of getArrayObjectExample() shows that the Vertica column type ARRAY[FLOAT] is type cast to Double[]:

queryText: SELECT ARRAY[ARRAY[0.0,0.1,0.2],ARRAY[1.0,1.1,1.2],ARRAY[2.0,2.1,2.2]]::ARRAY[ARRAY[FLOAT]] as array
Vertica driver returned a: class [Ljava.lang.Object;
 Value [0, 0]: 0.0 (class java.lang.Double)
 Value [0, 1]: 0.1 (class java.lang.Double)
 Value [0, 2]: 0.2 (class java.lang.Double)
 Value [1, 0]: 1.0 (class java.lang.Double)
 Value [1, 1]: 1.1 (class java.lang.Double)
 Value [1, 2]: 1.2 (class java.lang.Double)
 Value [2, 0]: 2.0 (class java.lang.Double)
 Value [2, 1]: 2.1 (class java.lang.Double)
 Value [2, 2]: 2.2 (class java.lang.Double)

ROW columns

Calling getObject() on a java.sql.ResultSet that contains a column of type ROW retrieves the column as a java.sql.Struct which contains an Object[] (itself retrievable with getAttributes()).

Each element of the Object[] represents an attribute from the struct, and each attribute has a corresponding Java type shown in the type conversion table above.

This example defines a ROW with the following attributes:


 Name    | Value        | Vertica Type | Java Type
-----------------------------------------------------------
 name    | Amy          | VARCHAR      | String
 date    | '07/10/2021' | DATE         | java.sql.Date
 id      | 5            | INT          | java.lang.Long
 current | false        | BOOLEAN      | java.lang.Boolean
package com.vertica.jdbc.test.samples;

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.Array;
import java.sql.Struct;


public class ComplexTypesSamples
{
    /**
     * Executes a query and gets a java.sql.Struct from the ResultSet. It then uses the Struct#getAttributes
     * method to get the contents of the struct as a Java Object [].
     * @param conn A Connection to a Vertica database
     * @throws SQLException
     */
    public static void getRowExample (Connection conn) throws SQLException {
        Statement stmt = conn.createStatement();

        final String queryText = "SELECT ROW('Amy', '07/10/2021'::Date, 5, false) as rowExample(name, date, id, current)";
        final String targetColumnName = "rowExample";

        System.out.println ("queryText: " + queryText);
        ResultSet rs = stmt.executeQuery(queryText);
        int targetColumnId = rs.findColumn (targetColumnName);

        while (rs.next ()) {
            // Get the java.sql.Array from the result set
            Object currentObject = rs.getObject (targetColumnId);
            assert (currentObject instanceof Struct);
            Struct rowStruct = (Struct)currentObject;

            Object[] attributes = rowStruct.getAttributes();

            // attributes.length should be 4 based on the queryText
            assert (attributes.length == 4);
            assert (attributes[0] instanceof String);
            assert (attributes[1] instanceof java.sql.Date);
            assert (attributes[2] instanceof java.lang.Long);
            assert (attributes[3] instanceof java.lang.Boolean);

            System.out.println ("attributes[0]: " + attributes[0] + " (" + attributes[0].getClass().getName() +")");
            System.out.println ("attributes[1]: " + attributes[1] + " (" + attributes[1].getClass().getName() +")");
            System.out.println ("attributes[2]: " + attributes[2] + " (" + attributes[2].getClass().getName() +")");
            System.out.println ("attributes[3]: " + attributes[3] + " (" + attributes[3].getClass().getName() +")");
        }
    }
}

The output of getRowExample() shows the attribute of each element and its corresponding Java type:


queryText: SELECT ROW('Amy', '07/10/2021'::Date, 5, false) as rowExample(name, date, id, current)
attributes[0]: Amy (java.lang.String)
attributes[1]: 2021-07-10 (java.sql.Date)
attributes[2]: 5 (java.lang.Long)
attributes[3]: false (java.lang.Boolean)

3.4.3.6 - Date types in JDBC

For the purposes of this page, a is defined as a date with a year that exceeds 9999.

Converting a date to a string

For the purposes of this page, a large date is defined as a date with a year that exceeds 9999.

If your database doesn't contain any large dates, then you can reliably call toString() to convert the dates to strings.

Otherwise, if your database contains large dates, you should use java.text.SimpleDateFormat and its format() method:

  1. Define a String format with java.text.SimpleDateFormat. The number of characters in yyyy in the format defines the minimum number of characters to use in the date.

  2. Call SimpleDateFormat.format() to convert the java.sql.Date object to a String.

Examples

For example, the following method returns a string when passed a java.sql.Date object as an argument. Here, the year part of the format, YYYY indicates that this format is compatible with all dates with at least four characters in its year.

#import java.sql.Date;

private String convertDate (Date date) {
    SimpleDateFormat dateFormat = new SimpleDateFormat ("yyyy-MM-dd");
    return dateFormat.format (date);
}

3.4.4 - Executing queries through JDBC

To run a query through JDBC:.

To run a query through JDBC:

  1. Connect with the Vertica database. See Creating and configuring a connection.

  2. Run the query.

The method you use to run the query depends on the type of query you want to run:

  • a DDL query that does not return a result set.

  • a DDL query that returns a result set.

  • a DML query

Executing DDL (data definition language) queries

To run DDL queries, such as CREATE TABLE and COPY, use the Statement.execute() method. You get an instance of this class by calling the createStatement method of your connection object.

The following example creates an instance of the Statement class and uses it to execute a CREATE TABLE and a COPY query:

Statement stmt = conn.createStatement();
stmt.execute("CREATE TABLE address_book (Last_Name char(50) default ''," +
    "First_Name char(50),Email char(50),Phone_Number char(50))");
stmt.execute("COPY address_book FROM 'address.dat' DELIMITER ',' NULL 'null'");

Executing queries that return result sets

Use the Statement class's executeQuery method to execute queries that return a result set, such as SELECT. To get the data from the result set, use methods such as getInt, getString, and getDouble to access column values depending upon the data types of columns in the result set. Use ResultSet.next to advance to the next row of the data set.

ResultSet rs = null;
rs = stmt.executeQuery("SELECT First_Name, Last_Name FROM address_book");
int x = 1;
while(rs.next()){
    System.out.println(x + ". " + rs.getString(1).trim() + " "
                       + rs.getString(2).trim());
    x++;
}

Executing DML (data manipulation language) queries using executeUpdate

Use the executeUpdate method for DML SQL queries that change data in the database, such as INSERT, UPDATE and DELETE which do not return a result set.

stmt.executeUpdate("INSERT INTO address_book " +
                   "VALUES ('Ben-Shachar', 'Tamar', 'tamarrow@example.com'," +
                   "'555-380-6466')");
stmt.executeUpdate("INSERT INTO address_book (First_Name, Email) " +
                   "VALUES ('Pete','pete@example.com')");

Executing stored procedures

You can create and execute stored procedures with CallableStatements.

To create a stored procedure:

Statement st = conn.createStatement();

String createSimpleSp = "CREATE OR REPLACE PROCEDURE raiseInt(IN x INT) LANGUAGE PLvSQL AS $$ " +
"BEGIN" +
    "RAISE INFO 'x = %', x;" +
"END;" +
"$$;";

st.execute(createSimpleSp);

To call a stored procedure:

String spCall = "CALL raiseInt (?)";
CallableStatement stmt = conn.prepareCall(spCall);
stmt.setInt(1, 42);

Stored procedures do not yet support OUT parameters. Instead, you can return and retrieve execution information with RAISE and getWarnings() respectively:

System.out.println(stmt.getWarnings().toString());

3.4.5 - Canceling JDBC queries

You can cancel JDBC queries with the Statement.cancel() method.

You can cancel JDBC queries with the Statement.cancel() method.

The following example creates a table jdbccanceltest and runs two queries, canceling the first:

import java.sql.Connection;
import java.sql.SQLException;
import java.sql.Statement;
import java.sql.ResultSet;
import java.sql.Array;
import java.sql.Struct;


public class CancelSamples
{
    /**
     * Sets up a large test table, queries its contents and cancels the query.
     * @param  conn A connection to a Vertica database
     * @throws SQLException
     */
    public static void sampleCancelTest(Connection conn) throws SQLException
    {
        setup(conn);
        try
        {
            runQueryAndCancel(conn);
            runSecondQuery(conn);
        }
        finally
        {
            cleanup(conn);
        }
    }

    // Set up table used in test.
    private static void setup(Connection conn) throws SQLException
    {
        System.out.println("Creating and loading table...");
        Statement stmt = conn.createStatement();
        String queryText = "DROP TABLE IF EXISTS jdbccanceltest";
        stmt.execute(queryText);

        queryText = "CREATE TABLE jdbccanceltest(id INTEGER, time TIMESTAMP)";
        stmt.execute(queryText);

        queryText = "INSERT INTO jdbccanceltest SELECT row_number() OVER(), slice_time "
                    + "FROM(SELECT slice_time FROM("
                    + "SELECT '2021-01-01'::timestamp s UNION ALL SELECT '2022-01-01'::timestamp s"
                    + ") sq TIMESERIES slice_time AS '1 second' OVER(ORDER BY s)) sq2";
        stmt.execute(queryText);
    }

    /**
     * Execute a long-running query and cancel it.
     * @param  conn A connection to a Vertica database
     * @throws SQLException
     */
    private static void runQueryAndCancel(Connection conn) throws SQLException
    {
        System.out.println("Running and canceling query...");
        Statement stmt = conn.createStatement();
        String queryText = "select id, time from jdbccanceltest";
        ResultSet rs = stmt.executeQuery(queryText);

        int i=0;
        stmt.cancel();
        try
        {
            while (rs.next()) ;
            i++;
        }
        catch (SQLException e)
        {
            System.out.println("Query canceled after retrieving " + i + " rows");
            System.out.println(e.getMessage());
        }
    }

    /**
     * Run a simple query to demonstrate that it can be run after
     * the previous query was canceled.
     * @param conn A connection to a Vertica database
     * @throws SQLException
     */
    private static void runSecondQuery(Connection conn) throws SQLException
    {
        String queryText = "select 1 from dual";
        Statement stmt = conn.createStatement();
        try
        {
            ResultSet rs = stmt.executeQuery(queryText);
            while (rs.next()) ;
        }
        catch (SQLException e)
        {
            System.out.println(e.getMessage());
            System.out.println("warning: no exception should have been thrown on query after cancel");
        }
    }

    /**
     * Clean up table used in test.
     * @param conn A connetion to a Vertica database
     * @throws SQLException
     */
    private static void cleanup(Connection conn) throws SQLException
    {
        String queryText = "drop table if exists jdbccanceltest";
        Statement stmt = conn.createStatement();
        stmt.execute(queryText);
    }
}

3.4.6 - Loading data through JDBC

You can use any of the following methods to load data via the JDBC interface:.

You can use any of the following methods to load data via the JDBC interface:

  • Executing a SQL INSERT statement to insert a single row directly.

  • Batch loading data using a prepared statement.

  • Bulk loading data from files or streams using COPY.

The following sections explain in detail how you load data using JDBC.

3.4.6.1 - Using a single row insert

The simplest way to insert data into a table is to use the SQL INSERT statement.

The simplest way to insert data into a table is to use the SQL INSERT statement. You can use this statement by instantiating a member of the Statement class, and use its executeUpdate() method to run your SQL statement.

The following code fragment demonstrates how you can create a Statement object and use it to insert data into a table named address_book:

Statement stmt = conn.createStatement();
stmt.executeUpdate("INSERT INTO address_book " +
             "VALUES ('Smith', 'John', 'jsmith@example.com', " +
             "'555-123-4567')");

This method has a few drawbacks: you need convert your data to string and escape any special characters in your data. A better way to insert data is to use prepared statements. See Batch inserts using JDBC prepared statements.

3.4.6.2 - Batch inserts using JDBC prepared statements

You can load batches of data into Vertica using prepared INSERT statements—server-side statements that you set up once, and then call repeatedly.

You can load batches of data into Vertica using prepared INSERT statements—server-side statements that you set up once, and then call repeatedly. You instantiate a member of the PreparedStatement class with a SQL statement that contains question mark placeholders for data. For example:

PreparedStatement pstmt = conn.prepareStatement(
                    "INSERT INTO customers(last, first, id) VALUES(?,?,?)");

You then set the parameters using data-type-specific methods on the PreparedStatement object, such as setString() and setInt(). Once your parameters are set, call the addBatch() method to add the row to the batch. When you have a complete batch of data ready, call the executeBatch() method to execute the insert batch.

Behind the scenes, the batch insert is converted into a COPY statement. When the connection's AutoCommit parameter is disabled, Vertica keeps the COPY statement open and uses it to load subsequent batches until the transaction is committed, the cursor is closed, or your application executes anything else (or executes any statement using another Statement or PreparedStatement object). Using a single COPY statement for multiple batch inserts makes loading data more efficient. If you are loading multiple batches, you should disable the AutoCommit property of the database to take advantage of this increased efficiency.

When performing batch inserts, experiment with various batch and row sizes to determine the settings that provide the best performance.

The following example demonstrates using a prepared statement to batch insert data.

import java.sql.*;
import java.util.Properties;

public class BatchInsertExample {
    public static void main(String[] args) {
        Properties myProp = new Properties();
        myProp.put("user", "ExampleUser");
        myProp.put("password", "password123");

     //Set streamingBatchInsert to True to enable streaming mode for batch inserts.
     //myProp.put("streamingBatchInsert", "True");

     Connection conn;
        try {
            conn = DriverManager.getConnection(
                            "jdbc:vertica://VerticaHost:5433/ExampleDB",
                            myProp);
            // establish connection and make a table for the data.
            Statement stmt = conn.createStatement();


            // Set AutoCommit to false to allow Vertica to reuse the same
            // COPY statement
            conn.setAutoCommit(false);


            // Drop table and recreate.
            stmt.execute("DROP TABLE IF EXISTS customers CASCADE");
            stmt.execute("CREATE TABLE customers (CustID int, Last_Name"
                            + " char(50), First_Name char(50),Email char(50), "
                            + "Phone_Number char(12))");
            // Some dummy data to insert.
            String[] firstNames = new String[] { "Anna", "Bill", "Cindy",
                            "Don", "Eric" };
            String[] lastNames = new String[] { "Allen", "Brown", "Chu",
                            "Dodd", "Estavez" };
            String[] emails = new String[] { "aang@example.com",
                            "b.brown@example.com", "cindy@example.com",
                            "d.d@example.com", "e.estavez@example.com" };
            String[] phoneNumbers = new String[] { "123-456-7890",
                            "555-444-3333", "555-867-5309",
                            "555-555-1212", "781-555-0000" };
            // Create the prepared statement
            PreparedStatement pstmt = conn.prepareStatement(
                            "INSERT INTO customers (CustID, Last_Name, " +
                            "First_Name, Email, Phone_Number)" +
                            " VALUES(?,?,?,?,?)");
            // Add rows to a batch in a loop. Each iteration adds a
            // new row.
            for (int i = 0; i < firstNames.length; i++) {
                // Add each parameter to the row.
                pstmt.setInt(1, i + 1);
                pstmt.setString(2, lastNames[i]);
                pstmt.setString(3, firstNames[i]);
                pstmt.setString(4, emails[i]);
                pstmt.setString(5, phoneNumbers[i]);
                // Add row to the batch.
                pstmt.addBatch();
            }

            try {
                // Batch is ready, execute it to insert the data
                pstmt.executeBatch();
            } catch (SQLException e) {
                System.out.println("Error message: " + e.getMessage());
                return; // Exit if there was an error
            }

            // Commit the transaction to close the COPY command
            conn.commit();


            // Print the resulting table.
            ResultSet rs = null;
            rs = stmt.executeQuery("SELECT CustID, First_Name, "
                            + "Last_Name FROM customers ORDER BY CustID");
            while (rs.next()) {
                System.out.println(rs.getInt(1) + " - "
                                + rs.getString(2).trim() + " "
                                + rs.getString(3).trim());
            }
            // Cleanup
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

The result of running the example code is:

1 - Anna Allen
2 - Bill Brown
3 - Cindy Chu
4 - Don Dodd
5 - Eric Estavez

Streaming batch inserts

By default, Vertica performs batch inserts by caching each row and inserting the cache when the user calls the executeBatch() method. Vertica also supports streaming batch inserts. A streaming batch insert adds a row to the database each time the user calls addBatch(). Streaming batch inserts improve database performance by allowing parallel processing and reducing memory demands.

To enable streaming batch inserts, set the streamingBatchInsert property to True. The preceding code sample includes a line enabling streamingBatchInsert mode. Remove the // comment marks to enable this line and activate streaming batch inserts.

The following table explains the various batch insert methods and how their behavior differs between default batch insert mode and streaming batch insert mode.

Method Default Batch Insert Behavior Streaming Batch Insert Behavior
addBatch() Adds a row to the row cache. Inserts a row into the database.
executeBatch() Adds the contents of the row cache to the database in a single action. Sends an end-of-batch message to the server and returns an array of integers indicating the success or failure of each addBatch() attempt.
clearBatch() Clears the row cache without inserting any rows. Not supported. Triggers an exception if used when streaming batch inserts are enabled.

Notes

  • Using the PreparedStatement.setFloat() method can cause rounding errors. If precision is important, use the .setDouble() method instead.

  • The PreparedStatement object caches the connection's AutoCommit property when the statement is prepared. Later changes to the AutoCommit property have no effect on the prepared statement.

3.4.6.2.1 - Error handling during batch loads

When loading individual batches, you can find how many rows were accepted and what rows were rejected (see Identifying Accepted and Rejected Rows for details).

When loading individual batches, you can find how many rows were accepted and what rows were rejected (see Identifying Accepted and Rejected Rows for details). If you have disabled the AutoCommit connection setting, other errors (such as disk space errors, for example) do not occur while inserting individual batches. This behavior is caused by having a single SQL COPY statement perform the loading of multiple consecutive batches (which makes the load process more efficient). It is only when the COPY statement closes that the batched data is committed and Vertica reports other types of errors.

Therefore, your bulk loading application should be prepared to check for errors when the COPY statement closes. You can trigger the COPY statement to close by:

  • ending the batch load transaction by calling Connection.commit()

  • closing the statement using Statement.close()

  • setting the connection's AutoCommit property to true before inserting the last batch in the load

3.4.6.2.2 - Identifying accepted and rejected rows (JDBC)

The return value of PreparedStatement.executeBatch is an integer array containing the success or failure status of inserting each row.

The return value of PreparedStatement.executeBatch is an integer array containing the success or failure status of inserting each row. A value 1 means the row was accepted and a value of -3 means that the row was rejected. In the case where an exception occurred during the batch execution, you can also get the array using BatchUpdateException.getUpdateCounts().

The following example extends the example shown in Batch inserts using JDBC prepared statements to retrieve this array and display the results the batch load.

import java.sql.*;
import java.util.Arrays;
import java.util.Properties;

public class BatchInsertErrorHandlingExample {
    public static void main(String[] args) {
        Properties myProp = new Properties();
        myProp.put("user", "ExampleUser");
        myProp.put("password", "password123");
        Connection conn;

        // establish connection and make a table for the data.
        try {
            conn = DriverManager.getConnection(
                            "jdbc:vertica://VerticaHost:5433/ExampleDB",
                            myProp);


            // Disable auto commit
            conn.setAutoCommit(false);

            // Create a statement
            Statement stmt = conn.createStatement();
            // Drop table and recreate.
            stmt.execute("DROP TABLE IF EXISTS customers CASCADE");
            stmt.execute("CREATE TABLE customers (CustID int, Last_Name"
                            + " char(50), First_Name char(50),Email char(50), "
                            + "Phone_Number char(12))");

            // Some dummy data to insert. The one row won't insert because
            // the phone number is too long for the phone column.
            String[] firstNames = new String[] { "Anna", "Bill", "Cindy",
                            "Don", "Eric" };
            String[] lastNames = new String[] { "Allen", "Brown", "Chu",
                            "Dodd", "Estavez" };
            String[] emails = new String[] { "aang@example.com",
                            "b.brown@example.com", "cindy@example.com",
                            "d.d@example.com", "e.estavez@example.com" };
            String[] phoneNumbers = new String[] { "123-456-789",
                            "555-444-3333", "555-867-53093453453",
                            "555-555-1212", "781-555-0000" };

            // Create the prepared statement
            PreparedStatement pstmt = conn.prepareStatement(
                            "INSERT INTO customers (CustID, Last_Name, " +
                            "First_Name, Email, Phone_Number)" +
                            " VALUES(?,?,?,?,?)");

            // Add rows to a batch in a loop. Each iteration adds a
            // new row.
            for (int i = 0; i < firstNames.length; i++) {
                // Add each parameter to the row.
                pstmt.setInt(1, i + 1);
                pstmt.setString(2, lastNames[i]);
                pstmt.setString(3, firstNames[i]);
                pstmt.setString(4, emails[i]);
                pstmt.setString(5, phoneNumbers[i]);
                // Add row to the batch.
                pstmt.addBatch();
            }

            // Integer array to hold the results of inserting
            // the batch. Will contain an entry for each row,
            // indicating success or failure.
            int[] batchResults = null;

            try {
                // Batch is ready, execute it to insert the data
                batchResults = pstmt.executeBatch();
            } catch (BatchUpdateException e) {
                // We expect an exception here, since one of the
                // inserted phone numbers is too wide for its column. All of the
                // rest of the rows will be inserted.
                System.out.println("Error message: " + e.getMessage());

                // Batch results isn't set due to exception, but you
                // can get it from the exception object.
                //
                // In your own code, you shouldn't assume the a batch
                // exception occurred, since exceptions can be thrown
                // by the server for a variety of reasons.
                batchResults = e.getUpdateCounts();
            }
            // You should also be prepared to catch SQLExceptions in your own
            // application code, to handle dropped connections and other general
            // problems.

            // Commit the transaction
            conn.commit();


            // Print the array holding the results of the batch insertions.
            System.out.println("Return value from inserting batch: "
                            + Arrays.toString(batchResults));
            // Print the resulting table.
            ResultSet rs = null;
            rs = stmt.executeQuery("SELECT CustID, First_Name, "
                            + "Last_Name FROM customers ORDER BY CustID");
            while (rs.next()) {
                System.out.println(rs.getInt(1) + " - "
                                + rs.getString(2).trim() + " "
                                + rs.getString(3).trim());
            }

            // Cleanup
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

Running the above example produces the following output on the console:

Error message: [Vertica][VJDBC](100172) One or more rows were rejected by the server.Return value from inserting batch: [1, 1, -3, 1, 1]
1 - Anna Allen
2 - Bill Brown
4 - Don Dodd
5 - Eric Estavez

Notice that the third row failed to insert because its phone number is too long for the Phone_Number column. All of the rest of the rows in the batch (including those after the error) were correctly inserted.

3.4.6.2.3 - Rolling back batch loads on the server

Batch loads always insert all of their data, even if one or more rows is rejected.

Batch loads always insert all of their data, even if one or more rows is rejected. Only the rows that caused errors in a batch are not loaded. When the database connection's AutoCommit property is true, batches automatically commit their transactions when they complete, so once the batch finishes loading, the data is committed.

In some cases, you may want all of the data in a batch to be successfully inserted—none of the data should be committed if an error occurs. The best way to accomplish this is to turn off the database connection's AutoCommit property to prevent batches from automatically committing themselves. Then, if a batch encounters an error, you can roll back the transaction after catching the BatchUpdateException caused by the insertion error.

The following example demonstrates performing a rollback if any error occurs when loading a batch.

import java.sql.*;
import java.util.Arrays;
import java.util.Properties;

public class RollbackBatchOnError {
    public static void main(String[] args) {
        Properties myProp = new Properties();
        myProp.put("user", "ExampleUser");
        myProp.put("password", "password123");
        Connection conn;
        try {
            conn = DriverManager.getConnection(
                            "jdbc:vertica://VerticaHost:5433/ExampleDB",
                            myProp);
            // Disable auto-commit. This will allow you to roll back a
            // a batch load if there is an error.
            conn.setAutoCommit(false);
            // establish connection and make a table for the data.
            Statement stmt = conn.createStatement();
            // Drop table and recreate.
            stmt.execute("DROP TABLE IF EXISTS customers CASCADE");
            stmt.execute("CREATE TABLE customers (CustID int, Last_Name"
                            + " char(50), First_Name char(50),Email char(50), "
                            + "Phone_Number char(12))");

            // Some dummy data to insert. The one row won't insert because
            // the phone number is too long for the phone column.
            String[] firstNames = new String[] { "Anna", "Bill", "Cindy",
                            "Don", "Eric" };
            String[] lastNames = new String[] { "Allen", "Brown", "Chu",
                            "Dodd", "Estavez" };
            String[] emails = new String[] { "aang@example.com",
                            "b.brown@example.com", "cindy@example.com",
                            "d.d@example.com", "e.estavez@example.com" };
            String[] phoneNumbers = new String[] { "123-456-789",
                            "555-444-3333", "555-867-53094535", "555-555-1212",
                            "781-555-0000" };
            // Create the prepared statement
            PreparedStatement pstmt = conn.prepareStatement(
                            "INSERT INTO customers (CustID, Last_Name, " +
                            "First_Name, Email, Phone_Number) "+
                            "VALUES(?,?,?,?,?)");
            // Add rows to a batch in a loop. Each iteration adds a
            // new row.
            for (int i = 0; i < firstNames.length; i++) {
                // Add each parameter to the row.
                pstmt.setInt(1, i + 1);
                pstmt.setString(2, lastNames[i]);
                pstmt.setString(3, firstNames[i]);
                pstmt.setString(4, emails[i]);
                pstmt.setString(5, phoneNumbers[i]);
                // Add row to the batch.
                pstmt.addBatch();
            }
            // Integer array to hold the results of inserting
            // the batch. Will contain an entry for each row,
            // indicating success or failure.
            int[] batchResults = null;
            try {
                // Batch is ready, execute it to insert the data
                batchResults = pstmt.executeBatch();
                // If we reach here, we inserted the batch without errors.
                // Commit it.
                System.out.println("Batch insert successful. Committing.");
                conn.commit();
            } catch (BatchUpdateException e) {
                    System.out.println("Error message: " + e.getMessage());
                    // Batch results isn't set due to exception, but you
                    // can get it from the exception object.
                    batchResults =  e.getUpdateCounts();
                    // Roll back the batch transaction.
                    System.out.println("Rolling back batch insertion");
                    conn.rollback();
            }
            catch  (SQLException e) {
                // General SQL errors, such as connection issues, throw
                // SQLExceptions. Your application should do something more
                // than just print a stack trace,
                e.printStackTrace();
            }
            System.out.println("Return value from inserting batch: "
                            + Arrays.toString(batchResults));
            System.out.println("Customers table contains:");


            // Print the resulting table.
            ResultSet rs = null;
            rs = stmt.executeQuery("SELECT CustID, First_Name, "
                            + "Last_Name FROM customers ORDER BY CustID");
            while (rs.next()) {
                System.out.println(rs.getInt(1) + " - "
                                + rs.getString(2).trim() + " "
                                + rs.getString(3).trim());
            }

            // Cleanup
            conn.close();
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

Running the above example prints the following on the system console:

Error message: [Vertica][VJDBC](100172) One or more rows were rejected by the server.Rolling back batch insertion
Return value from inserting batch: [1, 1, -3, 1, 1]
Customers table contains:

The return values indicate whether each rows was successfully inserted. The value 1 means the row inserted without any issues, and a -3 indicates the row failed to insert.

The customers table is empty since the batch insert was rolled back due to the error caused by the third column.

3.4.6.3 - Bulk loading using the COPY statement

One of the fastest ways to load large amounts of data into Vertica at once (bulk loading) is to use the COPY statement.

One of the fastest ways to load large amounts of data into Vertica at once (bulk loading) is to use the COPY statement. This statement loads data from a file stored on a Vertica host (or in a data stream) into a table in the database. You can pass the COPY statement parameters that define the format of the data in the file, how the data is to be transformed as it is loaded, how to handle errors, and how the data should be loaded. See the COPY documentation for details.

Only a superuser can use COPY to copy a file stored on a host, so you must connect to the database with a superuser account. If you want to have a non-superuser user bulk-load data, you can use COPY to load from a stream on the host (such as STDIN) rather than a file or stream data from the client (see Streaming data via JDBC). You can also perform a standard batch insert using a prepared statement, which uses the COPY statement in the background to load the data.

The following example demonstrates using the COPY statement through the JDBC to load a file name customers.txt into a new database table. This file must be stored on the database host to which your application connects—in this example, a host named VerticaHost.

import java.sql.*;
import java.util.Properties;
import com.vertica.jdbc.*;

public class COPYFromFile {
    public static void main(String[] args) {
        Properties myProp = new Properties();
        myProp.put("user", "ExampleAdmin"); // Must be superuser
        myProp.put("password", "password123");
        Connection conn;
        try {
            conn = DriverManager.getConnection(
                            "jdbc:vertica://VerticaHost:5433/ExampleDB",myProp);
            // Disable AutoCommit
            conn.setAutoCommit(false);
            Statement stmt = conn.createStatement();
            // Create a table to hold data.
            stmt.execute("DROP TABLE IF EXISTS customers;");
            stmt.execute("CREATE TABLE IF NOT EXISTS customers (Last_Name char(50) "
                            + "NOT NULL, First_Name char(50),Email char(50), "
                            + "Phone_Number char(15))");

             // Use the COPY command to load data. Use ENFORCELENGTH to reject
            // strings too wide for their columns.
            boolean result = stmt.execute("COPY customers FROM "
                            + " '/data/customers.txt' ENFORCELENGTH");

            // Determine if execution returned a count value, or a full result
            // set.
            if (result) {
                System.out.println("Got result set");
            } else {
                // Count will usually return the count of rows inserted.
                System.out.println("Got count");
                int rowCount = stmt.getUpdateCount();
                System.out.println("Number of accepted rows = " + rowCount);
            }


            // Commit the data load
            conn.commit();
        } catch (SQLException e) {
            System.out.print("Error: ");
            System.out.println(e.toString());
        }
    }
}

The example prints the following out to the system console when run (assuming that the customers.txt file contained two million valid rows):

Number of accepted rows = 2000000

3.4.6.4 - Streaming data via JDBC

There are two options to stream data from a file on the client to your Vertica database:.

There are two options to stream data from a file on the client to your Vertica database:

  • Use the VerticaCopyStream class to stream data in an object-oriented manner - details on the class are available in the JDBC documentation.

  • Execute a COPY LOCAL SQL statement to stream the data

The topics in this section explain how to use these options.

3.4.6.4.1 - Using VerticaCopyStream

The VerticaCopyStream class lets you stream data from the client system to a Vertica database.

The VerticaCopyStream class lets you stream data from the client system to a Vertica database. It lets you use COPY directly without first copying the data to a host in the database cluster. Using COPY to load data from the host requires superuser privileges to access the host's file system. The COPY statement used to load data from a stream does not require superuser privileges, so your client can connect with any user account that has INSERT privileges on the target table.

To copy streams into the database:

  1. Disable the database connections AutoCommit connection parameter.

  2. Instantiate a VerticaCopyStreamObject, passing it at least the database connection objects and a string containing a COPY statement to load the data. This statement must copy data from the STDIN into your table. You can use any parameters that are appropriate for your data load.

  3. Call VerticaCopyStreamObject.start() to start the COPY statement and begin streaming the data in any streams you have already added to the VerticaCopyStreamObject.

  4. Call VerticaCopyStreamObject.addStream() to add additional streams to the list of streams to send to the database. You can then call VerticaCopyStreamObject.execute() to stream them to the server.

  5. Optionally, call VerticaCopyStreamObject.getRejects() to get a list of rejected rows from the last .execute() call. The list of rejects is reset by each call to .execute() or .finish().

  6. When you are finished adding streams, call VerticaCopyStreamObject.finish() to send any remaining streams to the database and close the COPY statement.

  7. Call Connection.commit() to commit the loaded data.

Getting rejected rows

The VerticaCopyStreamObject.getRejects() method returns a List containing the row numbers of rows that were rejected after the previous .execute() method call. Each call to .execute() clears the list of rejected rows, so you need to call .getRejects() after each call to .execute(). Since .start() and .finish() also call .execute() to send any pending streams to the server, you should also call .getRejects() after these methods as well.

The following example demonstrates loading the content of five text files stored on the client system into a table.