Client libraries

• 1: Client driver and server version compatibility
• 2: Client drivers
• 2.1: Installing and configuring client drivers
• 2.1.1: Windows client driver installer
• 2.1.1.1: System prerequisites
• 2.1.1.1.1: .NET framework
• 2.1.1.1.2: Microsoft SQL server
• 2.1.1.2: Uninstalling, modifying, or repairing the client drivers and tools
• 2.1.2: FIPS client drivers
• 2.1.2.1: Installing the FIPS client driver for JDBC
• 2.1.2.2: Installing the FIPS client driver for ODBC and vsql
• 2.1.3: JDBC client driver
• 2.1.3.1: Installing the JDBC client driver
• 2.1.3.2: Modifying the Java CLASSPATH
• 2.1.4: ODBC client driver
• 2.1.4.1: Installing the ODBC client driver
• 2.1.4.2: Upgrading and downgrading ODBC
• 2.1.4.3: Uninstalling ODBC
• 2.1.4.4: Creating an ODBC data source name (DSN)
• 2.1.4.4.1: Creating an ODBC DSN for Linux
• 2.1.4.4.1.1: Testing an ODBC DSN using isql
• 2.1.4.4.2: Creating an ODBC DSN for windows clients
• 2.1.4.4.2.1: Setting up an ODBC DSN
• 2.1.4.4.2.2: Encrypting passwords on ODBC DSN
• 2.1.4.4.2.3: Testing an ODBC DSN using Excel
• 2.1.4.4.3: Creating an ODBC DSN for macOS clients
• 2.1.4.4.3.1: Testing an ODBC DSN using iodbctest
• 2.1.4.4.4: ODBC DSN connection properties
• 2.1.4.4.5: Setting DSN connection properties
• 2.1.4.5: ODBC driver settings
• 2.1.4.6: Configuring ODBC logs
• 2.1.5: Python client drivers
• 2.1.5.1: Installing Python client drivers
• 2.1.6: Node.js client driver
• 2.1.7: Go client driver
• 2.1.8: OLE DB client driver
• 2.1.8.1: Installing the OLE DB client driver
• 2.1.8.1.1: OLE DB connection properties
• 2.1.8.1.2: Configuring OLE DB logs
• 2.1.9: ADO.NET client driver
• 2.1.9.1: Installing the ADO.NET client driver
• 2.1.9.2: Log properties
• 2.2: Upgrading the client drivers
• 2.3: Setting a client connection label
• 2.4: Using legacy drivers
• 3: Accessing Vertica
• 3.1: C/C++
• 3.1.1: ODBC architecture
• 3.1.2: ODBC feature support
• 3.1.3: Vertica and ODBC data type translation
• 3.1.4: ODBC header file
• 3.1.5: Canceling ODBC queries
• 3.1.6: Connecting to the database
• 3.1.7: Load balancing
• 3.1.8: Configuring TLS for ODBC Clients
• 3.1.9: Connection failover
• 3.1.10: Prompting windows users for missing connection properties
• 3.1.11: Prompting windows users for passwords
• 3.1.12: Setting the locale and encoding for ODBC sessions
• 3.1.13: AUTOCOMMIT and ODBC transactions
• 3.1.14: Retrieving data
• 3.1.15: Loading data
• 3.1.15.1: Using a single row insert
• 3.1.15.2: Using prepared statements
• 3.1.15.3: Using batch inserts
• 3.1.15.3.1: Tracking load status (ODBC)
• 3.1.15.3.2: Error handling during batch loads
• 3.1.15.4: Using the COPY statement
• 3.1.15.5: Streaming data from the client using COPY LOCAL
• 3.2: C#
• 3.2.1: ADO.NET data types
• 3.2.2: Setting the locale for ADO.NET sessions
• 3.2.3: Connecting to the database
• 3.2.3.1: Configuring TLS for ADO.NET
• 3.2.3.2: Opening and closing the database connection (ADO.NET)
• 3.2.3.3: ADO.NET connection properties
• 3.2.3.4: Load balancing in ADO.NET
• 3.2.3.5: ADO.NET connection failover
• 3.2.4: Querying the database using ADO.NET
• 3.2.4.1: Inserting data (ADO.NET)
• 3.2.4.1.1: Using parameters
• 3.2.4.1.2: Creating and rolling back transactions
• 3.2.4.1.2.1: Setting the transaction isolation level
• 3.2.4.2: Reading data (ADO.Net)
• 3.2.4.3: Loading data through ADO.Net
• 3.2.4.3.1: Using the Vertica data adapter
• 3.2.4.3.2: Using batch inserts and prepared statements
• 3.2.4.3.3: Streaming data via ADO.NET
• 3.2.4.3.3.1: Streaming from the client via VerticaCopyStream
• 3.2.4.3.3.2: Using copy with ADO.NET
• 3.2.5: Canceling ADO.NET queries
• 3.2.6: Handling messages
• 3.2.7: Getting table metadata
• 3.3: Go
• 3.4: Java
• 3.4.1: JDBC feature support
• 3.4.2: Creating and configuring a connection
• 3.4.2.1: JDBC connection properties
• 3.4.2.2: Setting and getting connection property values
• 3.4.2.3: Configuring TLS for JDBC clients
• 3.4.2.4: Setting and returning a client connection label
• 3.4.2.5: Setting the locale for JDBC sessions
• 3.4.2.6: Changing the transaction isolation level
• 3.4.2.7: JDBC connection pools
• 3.4.2.8: Load balancing in JDBC
• 3.4.2.9: JDBC connection failover
• 3.4.3: JDBC data types
• 3.4.3.1: The VerticaTypes class
• 3.4.3.2: Numeric data alias conversion
• 3.4.3.3: Using intervals with JDBC
• 3.4.3.4: UUID values
• 3.4.3.5: Complex types in JDBC
• 3.4.3.6: Date types in JDBC
• 3.4.4: Executing queries through JDBC
• 3.4.5: Canceling JDBC queries
• 3.4.6: Loading data through JDBC
• 3.4.6.1: Using a single row insert
• 3.4.6.2: Batch inserts using JDBC prepared statements
• 3.4.6.2.1: Error handling during batch loads
• 3.4.6.2.2: Identifying accepted and rejected rows (JDBC)
• 3.4.6.2.3: Rolling back batch loads on the server
• 3.4.6.3: Bulk loading using the COPY statement
• 3.4.6.4: Streaming data via JDBC
• 3.4.6.4.1: Using VerticaCopyStream
• 3.4.6.4.2: Using COPY LOCAL with JDBC
• 3.4.7: Handling errors
• 3.4.7.1: SQLState mapping to Java exception classes
• 3.4.8: Routing JDBC queries directly to a single node
• 3.4.8.1: Creating tables and projections for use with the routable query API
• 3.4.8.2: Creating a connection for routable queries
• 3.4.8.3: Defining the query for routable queries using the VerticaRoutableExecutor class
• 3.4.8.4: Defining the query for routable queries using the VGet class
• 3.4.8.5: Routable query performance and troubleshooting
• 3.4.8.6: Pre-segmenting data using VHash
• 3.4.9: Timezones and daylight savings time
• 3.5: JavaScript
• 3.6: Perl
• 3.6.1: Configuring a Perl development environment
• 3.6.2: Connecting to Vertica using Perl
• 3.6.2.1: Setting ODBC connection parameters in Perl
• 3.6.2.2: Setting Perl DBI connection attributes
• 3.6.2.3: Connecting from Perl without a DSN
• 3.6.3: Executing statements using Perl
• 3.6.4: Batch loading data using Perl
• 3.6.5: Using COPY LOCAL to load data in Perl
• 3.6.6: Querying using Perl
• 3.6.7: Conversions between Perl and Vertica data types
• 3.6.8: Perl unicode support
• 3.7: Python
• 3.7.1: Configuring the ODBC run-time environment on Linux
• 3.7.2: Querying the database with pyodbc
• 3.8: PHP
• 3.8.1: Configuring a PHP development environment
• 3.8.2: PHP unicode support
• 3.8.3: Querying the database using PHP
• 4: Managing query execution between the client and Vertica
• 4.1: ResultBufferSize
• 4.2: Multiple active result sets (MARS)

1 - Client driver and server version compatibility

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.

2 - Client drivers

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. The following table lists the required client drivers for each access method:

2.1.1 - Windows client driver 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:

• ODBC

• JDBC

• OLE DB

• vsql

2.1.1.1 - System prerequisites

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.

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. 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)

  Note

  For SQL Server 2012, you can use either SQL Server 2012 or SQL Server 2012 SP1.

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:

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.

The installer provides three options:

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.

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). 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
   

   Note

   If you are using FIPS with BouncyCastle, you must create all client keys and certificates with the BCFKS store type, including the Vertica-to-Kafka keys and certificates.

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. 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:

• Creating an ODBC DSN for Linux
• ODBC driver settings

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. 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. 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. For your Java client code to access Vertica, you must add to the CLASSPATH the directory containing the Vertica JDBC .jar.

Using symbolic links for the CLASSPATH

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:

• C/C++

• Python

• Perl

• PHP

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. 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:

     Note

     If the client driver is already installed on your system (either from a manual installation or from automatic installation from the Vertica RPM) and you attempt to reinstall them manually, you will receive error messages. To bypass these errors and overwrite the existing driver installations, use the --force flag.

     $ 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

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

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. 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. 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. 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:

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. 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).

   Note

   The method you use to open the ODBC Administrator depends on your version of Windows. Differences between Windows versions and Start Menu customizations could require you to take a different action to open the ODBC Administrator.

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.

   Note

   If you have installed more than one version of the Vertica client drivers on your Windows client system, you may see multiple versions of the driver in this list. Choose the version that you know is compatible with your client application and Vertica Analytic Database server. If you are unsure, use the latest version of the driver.

   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.

      Caution

      Passwords entered into the Password box are saved, in plaintext, to the Windows registry.

   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. 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.

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. 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. 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. To set these parameters, see Setting DSN connection properties.

Required connection properties

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

Optional properties

Advanced settings

Identification

OAuth connection properties

The following connection properties pertain to OAuth in ODBC.

Encryption

Third-party compatibility

Kerberos connection properties

Use the following properties for client authentication using Kerberos.

See also

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 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);
  

  Note

  In the connection string ';' is a reserved symbol. If you need to set multiple properties as part of the ConnSettings property use '%3B' in place of ';'. Also use '+' instead of spaces.

  For example:

  sqlRet = SQLDriverConnect(sql_hDBC, 0, (SQLCHAR*)"DSN=Vertica SQL;ConnSettings=set+search_path+to+a,b,c%3Bset+locale=ch;SSLMode=prefer", 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

• 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.

  Note

  While both UTF-16 and UTF-8 are valid settings for the DataDirect driver manager, UTF-16 is recommended.

  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 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.

   Important

   You must have administrator privileges to successfully complete the next step.

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
     

   Note

   Should you want to later disable the logs, you can use the same wevtutil sl command, substituting /e:false in place of /e:true when you issue the statement. Alternatively, you can enable or disable logs within the Windows Event Viewer itself.

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.

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.

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.

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. 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. For details, see vertica-sql-go.

2.1.8 - OLE DB client driver

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:

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. You access the Connection Manager from within Visual Studio.

These connection parameters appear on the Connection page.

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.

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. 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.

   Important

   You must have administrator privileges to successfully complete the next step.

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
      

   Note

   Should you want to later disable the logs, you can use the same wevtutil sl command, substituting /e:false in place of /e:true when you issue the statement. Alternatively, you can enable or disable logs within the Windows Event Viewer itself.

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.

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 Vertica with C# .

2.1.9.1 - Installing the ADO.NET client driver

Prerequisites

The ADO.NET client driver requires the following:

• A supported operating system.

• At least 512MB of memory

• A supported version of .NET Core or .NET Framework. For details, see the Microsoft documentation:

  • Install .NET on Windows
  • Install .NET on macOS
  • Install .NET on Linux

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

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 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. 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.

• JDBC connection properties
• ODBC DSN connection properties
• ADO.NET connection properties

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. 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:

3.1 - C/C++

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:

• 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 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. This section explains several data types require special handling.

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

• Data types
• Using LONG VARCHAR and LONG VARBINARY data types with ODBC
• Using GEOMETRY and GEOGRAPHY data types in ODBC

• SQL Data Types in the Microsoft ODBC reference documentation

3.1.4 - ODBC header file

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.

SQLSetConnectAttr()
SQLGetConnectAttr()

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

SQLSetConnectAttr()
SQLGetConnectAttr()

3.1.5 - Canceling ODBC queries

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. 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.

   Note

   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.

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

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

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.

3.1.9 - 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.

// 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 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 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.

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:

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

  • On Linux and other UNIX-like platforms: Creating an ODBC DSN for Linux

  • On Windows platforms, set the locale in the ODBC DSN configuration editor's Locale field on the Server Settings tab. See Creating an ODBC DSN for windows clients for detailed information.

• 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. 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:

• 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);
}