OpenText Analytics Database 26.2.x – Functions

Sql-Reference: Aggregate functions

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Aggregate functions summarize data over groups of rows from a query result set. The groups are specified using the GROUP BY clause. They are allowed only in the select list and in the HAVING and ORDER BY clauses of a SELECT statement (as described in Aggregate expressions).

Except for COUNT, these functions return a null value when no rows are selected. In particular, SUM of no rows returns NULL, not zero.

In some cases, you can replace an expression that includes multiple aggregates with a single aggregate of an expression. For example SUM(x) + SUM(y) can be expressed as as SUM(x+y) if neither argument is NULL.

OpenText™ Analytics Database does not support nested aggregate functions.

You can use some of the simple aggregate functions as analytic (window) functions. See Analytic functions for details. See also SQL analytics.

Some collection functions also behave as aggregate functions.

Note

All functions in this section that have an analytic function counterpart are appended with [aggregate] to avoid confusion between the two.

Sql-Reference: Analytic functions

Mon, 01 Jan 0001 00:00:00 +0000

Note

All analytic functions in this section with an aggregate counterpart are appended with [Analytics] in the heading to avoid confusion between the two function types.

OpenText™ Analytics Database analytics are SQL functions based on the ANSI 99 standard. These functions handle complex analysis and reporting tasks—for example:

Rank the longest-standing customers in a particular state.
Calculate the moving average of retail volume over a specified time.
Find the highest score among all students in the same grade.
Compare the current sales bonus that salespersons received against their previous bonus.

Analytic functions return aggregate results but they do not group the result set. They return the group value multiple times, once per record. You can sort group values, or partitions, using a window ORDER BY clause, but the order affects only the function result set, not the entire query result set.

Syntax

General

analytic-function(arguments) OVER(
  [ window-partition-clause ]
  [ window-order-clause [ window-frame-clause ] ]
)

With named window

analytic-function(arguments) OVER(
  [  named-window [ window-frame-clause ] ]
)

Parameters

analytic-function(arguments): An OpenText™ Analytics Database analytic function and its arguments.
OVER: Specifies how to partition, sort, and window frame function input with respect to the current row. The input data is the result set that the query returns after it evaluates FROM, WHERE, GROUP BY, and HAVING clauses.
An empty OVER clause provides the best performance for single threaded queries on a single node.
window-partition-clause: Groups input rows according to one or more columns or expressions.
If you omit this clause, no grouping occurs and the analytic function processes all input rows as a single partition.
window-order-clause: Optionally specifies how to sort rows that are supplied to the analytic function. If the OVER clause also includes a partition clause, rows are sorted within each partition.
window-frame-clause: Only valid for some analytic functions, specifies as input a set of rows relative to the row that is currently being evaluated by the analytic function. After the function processes that row and its window, the database advances the current row and adjusts the window boundaries accordingly.
named-window: The name of a window that you define in the same query with a window-name-clause. This definition encapsulates window partitioning and sorting. Named windows are useful when the query invokes multiple analytic functions with similar OVER clauses.
A window name clause cannot specify a window frame clause. However, you can qualify the named window in an OVER clause with a window frame clause.

Requirements

The following requirements apply to analytic functions:

All require an OVER clause. Each function has its own OVER clause requirements. For example, you can supply an empty OVER clause for some analytic aggregate functions such as SUM. For other functions, window frame and order clauses might be required, or might be invalid.
Analytic functions can be invoked only in a query's SELECT and ORDER BY clauses.
Analytic functions cannot be nested. For example, the following query is not allowed:
```
=> SELECT MEDIAN(RANK() OVER(ORDER BY sal) OVER()).
```
WHERE, GROUP BY and HAVING operators are technically not part of the analytic function. However, they determine input to that function.

Sql-Reference: Client connection functions

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This section contains client connection management functions specific to OpenText™ Analytics Database.

Sql-Reference: Data-type-specific functions

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OpenText™ Analytics Database provides functions for use with specific data types, described in this section.

Sql-Reference: Database Designer functions

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Database Designer functions perform the following operations, generally performed in the following order:

Important

You can also use meta-function DESIGNER_SINGLE_RUN, which encapsulates all of these steps with a single call. The meta-function iterates over all queries within a specified timespan, and returns with a design ready for deployment.

For detailed information, see Workflow for running Database Designer programmatically. For information on required privileges, see Privileges for running Database Designer functions

Caution

Before running Database Designer functions on an existing schema, back up the current design by calling EXPORT_CATALOG.

Create a design

DESIGNER_CREATE_DESIGN directs Database Designer to create a design.

Set design properties

The following functions let you specify design properties:

DESIGNER_SET_DESIGN_TYPE: Specifies whether the design is comprehensive or incremental.
DESIGNER_DESIGN_PROJECTION_ENCODINGS: Analyzes encoding in the specified projections and creates a script that implements encoding recommendations.
DESIGNER_SET_DESIGN_KSAFETY: Sets the K-safety value for a comprehensive design.
DESIGNER_SET_OPTIMIZATION_OBJECTIVE: Specifies whether the design optimizes for query or load performance.
DESIGNER_SET_PROPOSE_UNSEGMENTED_PROJECTIONS: Enables inclusion of unsegmented projections in the design.

Populate a design

The following functions let you add tables and queries to your Database Designer design:

DESIGNER_ADD_DESIGN_TABLES: Adds the specified tables to a design.
DESIGNER_ADD_DESIGN_QUERY, DESIGNER_ADD_DESIGN_QUERIES, DESIGNER_ADD_DESIGN_QUERIES_FROM_RESULTS: Adds queries to the design and weights them.

Create design and deployment scripts

The following functions populate the Database Designer workspace and create design and deployment scripts. You can also analyze statistics, deploy the design automatically, and drop the workspace after the deployment:

DESIGNER_RUN_POPULATE_DESIGN_AND_DEPLOY: Populates the design and creates design and deployment scripts.
DESIGNER_WAIT_FOR_DESIGN: Waits for a currently running design to complete.

Reset a design

DESIGNER_RESET_DESIGN discards all the run-specific information of the previous Database Designer build or deployment of the specified design but retains its configuration.

Get design data

The following functions display information about projections and scripts that the Database Designer created:

DESIGNER_OUTPUT_ALL_DESIGN_PROJECTIONS: Sends to standard output DDL statements that define design projections.
DESIGNER_OUTPUT_DEPLOYMENT_SCRIPT: Sends to standard output a design's deployment script.

Cleanup

The following functions cancel any running Database Designer operation or drop a Database Designer design and all its contents:

DESIGNER_CANCEL_POPULATE_DESIGN: Cancels population or deployment operation for the specified design if it is currently running.
DESIGNER_DROP_DESIGN: Removes the schema associated with the specified design and all its contents.
DESIGNER_DROP_ALL_DESIGNS: Removes all Database Designer-related schemas associated with the current user.

Sql-Reference: Directed queries functions

Mon, 01 Jan 0001 00:00:00 +0000

The following meta-functions let you batch export query plans as directed queries from one OpenText™ Analytics Database and import those directed queries to another database.

Sql-Reference: Error-handling functions

Mon, 01 Jan 0001 00:00:00 +0000

Error-handling functions take a string and return the string when the query is executed.

Sql-Reference: Flex functions

Mon, 01 Jan 0001 00:00:00 +0000

This section contains helper functions for use in working with flex tables and flexible columns for complex types. You can use these functions with flex tables, their associated flex_table_keys tables and flex_table_view views, and flexible columns in external tables. These functions do not apply to other tables.

For more information about flex tables, see Flex tables. For more information about flexible columns for complex types, see Flexible complex types.

Flex functions allow you to manage and query flex tables. You can also use the map functions to query flexible complex-type columns in non-flex tables.

Sql-Reference: Formatting functions

Mon, 01 Jan 0001 00:00:00 +0000

Formatting functions provide a powerful tool set for converting various data types (DATE/TIME, INTEGER, FLOATING POINT) to formatted strings and for converting from formatted strings to specific data types.

Sql-Reference: Geospatial functions

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Geospatial functions manipulate complex two-dimensional spatial objects and store them in a database according to the Open Geospatial Consortium (OGC) standards.

Function naming conventions

The geospatial functions use the following naming conventions:

Most ST_function-name functions are compliant with the latest OGC standard OGC SFA-SQL version 1.2.1 (reference. number is OGC 06-104r4, date: 2010-08-04). Currently, some ST_function-name functions may not support all data types. Each function page contains details about the supported data types.

Note
Some functions, such as ST_GeomFromText, are based on previous versions of the standard.
The STV_function-name functions are unique to OpenText™ Analytics Database and not compliant with OGC standards. Each function page explains its functionality in detail.

Verifying spatial objects validity

Many spatial functions do not validate their parameters. If you pass an invalid spatial object to an ST_ or STV_ function, the function might return an error or produce incorrect results.

To avoid this issue, OpenText recommends that you first run ST_IsValid on all spatial objects to validate the parameters. If your object is not valid, run STV_IsValidReason to get information about the location of the invalidity.

Sql-Reference: Hadoop functions

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This section contains functions to manage interactions with Hadoop.

Sql-Reference: Machine learning functions

Mon, 01 Jan 0001 00:00:00 +0000

Machine learning functions let you work with your data set in different stages of the data analysis process:

Preparing models
Training models
Evaluating models
Applying models
Managing models

Some OpenText™ Analytics Database machine learning functions are implemented as database UDx functions, while others are implemented as meta-functions:

A UDx function accepts an input relation name from a FROM clause. The SELECT statement that calls the functions is composable—it can be used as a sub-query in another SELECT statement.
A meta-function accepts the input relation name as a single-quoted string passed to it as an argument or a named parameter. The data that the SELECT statement returns cannot be used in a sub-query. Machine learning meta-functions do not support temporary tables.

All machine learning functions automatically cast NUMERIC arguments to FLOAT.

Important

Before using a machine learning function, be aware that any open transaction on the current session might be committed.

Sql-Reference: Management functions

Mon, 01 Jan 0001 00:00:00 +0000

OpenText™ Analytics Database has functions to manage various aspects of database operation, such as sessions, privileges, projections, and the catalog.

Sql-Reference: Match and search functions

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This section contains functions for text search and regular expressions, and functions used in the MATCH clause.

Sql-Reference: Mathematical functions

Mon, 01 Jan 0001 00:00:00 +0000

Some of these functions are provided in multiple forms with different argument types. Except where noted, any given form of a function returns the same data type as its argument. The functions working with DOUBLE PRECISION data could vary in accuracy and behavior in boundary cases depending on the host system.

Sql-Reference: NULL-handling functions

Mon, 01 Jan 0001 00:00:00 +0000

NULL-handling functions take arguments of any type, and their return type is based on their argument types.

Sql-Reference: Performance analysis functions

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The functions in this section support profiling and analyzing database and query performance.

Sql-Reference: Stored procedure functions

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This section contains functions for managing stored procedures.

Sql-Reference: System information functions

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These functions provide information about the current system state. A superuser has unrestricted access to all system information, but users can view only information about their own, current sessions.

Sql-Reference: Vector functions

Mon, 01 Jan 0001 00:00:00 +0000

Vector functions perform calculations on vectors expressed as ARRAY inputs of types INT, FLOAT, or NUMERIC. The results of these calculations are returned as measurements in FLOAT.

You can use these functions for semantic comparison to determine the vector similarity, or distance, between data vectors.