CREATE FUNCTION statements

• 1: CREATE AGGREGATE FUNCTION
• 2: CREATE ANALYTIC FUNCTION
• 3: CREATE FILTER
• 4: CREATE FUNCTION (scalar)
• 5: CREATE FUNCTION (SQL)
• 6: CREATE PARSER
• 7: CREATE SOURCE
• 8: CREATE TRANSFORM FUNCTION

1 - CREATE AGGREGATE FUNCTION

Adds a user-defined aggregate function (UDAF) to the catalog. The library containing the function must have been previously added using CREATE LIBRARY.

CREATE AGGREGATE FUNCTION automatically determines the function parameters and return value from data supplied by the factory class. Vertica supports overloading aggregate functions. When you call the SQL function, Vertica passes the input table to the function to process.

User-defined aggregate functions run in unfenced mode only.

Syntax

CREATE [ OR REPLACE ] AGGREGATE FUNCTION [ IF NOT EXISTS ]
  [[database.]schema.]function AS
  [ LANGUAGE 'language' ]
  NAME 'factory'
  LIBRARY library
  [ NOT FENCED ];

Arguments

OR REPLACE

If a function with the same name and arguments exists, replace it. You can use this to change between fenced and unfenced modes, for example. If you do not use this directive and the function already exists, the CREATE statement returns with a rollback error.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

IF NOT EXISTS

If a function with the same name and arguments exists, return without creating the function.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

[database.]schema

Database and schema. The default schema is public. If you specify a database, it must be the current database.

function

Name of the function to create. This is the name used in SQL invocations of the function. It does not need to match the name of the factory, but it is less confusing if they are the same or similar.

The function name must conform to the restrictions on Identifiers.

LANGUAGE 'language'

The language used to develop this function, currently C++ only (the default).

NAME 'factory'

Name of the factory class that generates the function instance.

LIBRARY library

Name of the shared library that contains the function. This library must have already been loaded by CREATE LIBRARY.

NOT FENCED

Indicates that the function runs in unfenced mode. Aggregate functions cannot be run in fenced mode.

Privileges

Non-superuser:

• CREATE privilege on the function's schema

• USAGE privilege on the function's library

Examples

The following example demonstrates loading a library named AggregateFunctions and then defining functions named ag_avg and ag_cat. The functions are mapped to the AverageFactory and ConcatenateFactory classes in the library:

=> CREATE LIBRARY AggregateFunctions AS '/opt/vertica/sdk/examples/build/AggregateFunctions.so';
CREATE LIBRARY
=> CREATE AGGREGATE FUNCTION ag_avg AS LANGUAGE 'C++' NAME 'AverageFactory'
   library AggregateFunctions;
CREATE AGGREGATE FUNCTION
=> CREATE AGGREGATE FUNCTION ag_cat AS LANGUAGE 'C++' NAME 'ConcatenateFactory'
   library AggregateFunctions;
CREATE AGGREGATE FUNCTION
=> \x
Expanded display is on.
select * from user_functions;
-[ RECORD 1 ]----------+------------------------------------------------------------------
schema_name            | public
function_name          | ag_avg
procedure_type         | User Defined Aggregate
function_return_type   | Numeric
function_argument_type | Numeric
function_definition    | Class 'AverageFactory' in Library 'public.AggregateFunctions'
volatility             |
is_strict              | f
is_fenced              | f
comment                |
-[ RECORD 2 ]----------+------------------------------------------------------------------
schema_name            | public
function_name          | ag_cat
procedure_type         | User Defined Aggregate
function_return_type   | Varchar
function_argument_type | Varchar
function_definition    | Class 'ConcatenateFactory' in Library 'public.AggregateFunctions'
volatility             |
is_strict              | f
is_fenced              | f
comment                |

See also

• DROP AGGREGATE FUNCTION
• USER_FUNCTIONS
• Developing user-defined extensions (UDxs)
• Aggregate functions (UDAFs)

2 - CREATE ANALYTIC FUNCTION

Adds a user-defined analytic function (UDAnF) to the catalog. The library containing the function must have been previously added using CREATE LIBRARY.

CREATE ANALYTIC FUNCTION automatically determines the function parameters and return value from data supplied by the factory class. Vertica supports overloading analytic functions. When you call the SQL function, Vertica passes the input table to the function in the library to process.

Syntax

CREATE [ OR REPLACE ] ANALYTIC FUNCTION [ IF NOT EXISTS ]
    [[database.]schema.]function AS
    [ LANGUAGE 'language' ]
    NAME 'factory'
    LIBRARY library
    [ FENCED | NOT FENCED ]

Arguments

OR REPLACE

If a function with the same name and arguments exists, replace it. You can use this to change between fenced and unfenced modes, for example. If you do not use this directive and the function already exists, the CREATE statement returns with a rollback error.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

IF NOT EXISTS

If a function with the same name and arguments exists, return without creating the function.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

[database.]schema

Database and schema. The default schema is public. If you specify a database, it must be the current database.

function

Name of the function to create. This is the name used in SQL invocations of the function. It does not need to match the name of the factory, but it is less confusing if they are the same or similar.

The function name must conform to the restrictions on Identifiers.

LANGUAGE 'language'

Language used to develop this function, one of the following:

• C++ (default)

• Java

NAME 'factory'

Name of the factory class that generates the function instance.

LIBRARY library

Name of the library that contains the function. This library must already be loaded by CREATE LIBRARY.

FENCED | NOT FENCED

Enables or disables fenced mode for this function.

Default: FENCED

Privileges

Non-superuser:

• CREATE privilege on the function's schema

• USAGE privilege on the function's library

Examples

This example creates an analytic function named an_rank based on the factory class named RankFactory in the AnalyticFunctions library:

=> CREATE ANALYTIC FUNCTION an_rank AS LANGUAGE 'C++'
   NAME 'RankFactory' LIBRARY AnalyticFunctions;

See also

3 - CREATE FILTER

Adds a user-defined load filter function to the catalog. The library containing the filter function must have been previously added using CREATE LIBRARY.

CREATE FILTER automatically determines the function parameters and return value from data supplied by the factory class. Vertica supports overloading load filter functions. When you call the SQL function, Vertica passes the input table to the function in the library to process.

Syntax

CREATE [ OR REPLACE ] FILTER [ IF NOT EXISTS ]
   [[database.]schema.]function AS
   [ LANGUAGE 'language' ]
   NAME 'factory' LIBRARY library
   [ FENCED | NOT FENCED ]

Arguments

OR REPLACE

If a function with the same name and arguments exists, replace it. You can use this to change between fenced and unfenced modes, for example. If you do not use this directive and the function already exists, the CREATE statement returns with a rollback error.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

IF NOT EXISTS

If a function with the same name and arguments exists, return without creating the function.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

[database.]schema

Database and schema. The default schema is public. If you specify a database, it must be the current database.

function

Name of the function to create. This is the name used in SQL invocations of the function. It does not need to match the name of the factory, but it is less confusing if they are the same or similar.

The function name must conform to the restrictions on Identifiers.

LANGUAGE 'language'

The language used to develop this function, one of the following:

• C++ (default)

• Java

• Python

NAME 'factory'

Name of the factory class that generates the function instance. This is the same name used by the RegisterFactory class.

LIBRARY library

Name of the C++ library shared object file, Python file, or Java Jar file. This library must already have been loaded by CREATE LIBRARY.

FENCED | NOT FENCED

Enables or disables fenced mode for this function.

Default: FENCED

Privileges

Superuser

Examples

The following example demonstrates loading a library named iConverterLib, then defining a filter function named Iconverter that is mapped to the iConverterFactory factory class in the library:

=> CREATE LIBRARY iConverterLib as '/opt/vertica/sdk/examples/build/IconverterLib.so';
CREATE LIBRARY
=> CREATE FILTER Iconverter AS LANGUAGE 'C++' NAME 'IconverterFactory' LIBRARY IconverterLib;
CREATE FILTER FUNCTION
=> \x
Expanded display is on.
=> SELECT * FROM user_functions;
-[ RECORD 1 ]----------+--------------------
schema_name            | public
function_name          | Iconverter
procedure_type         | User Defined Filter
function_return_type   |
function_argument_type |
function_definition    |
volatility             |
is_strict              | f
is_fenced              | f
comment                |

See also

• DROP FILTER
• USER_FUNCTIONS
• User-defined load (UDL)

4 - CREATE FUNCTION (scalar)

Adds a user-defined scalar function (UDSF) to the catalog. The library containing the function must have been previously added using CREATE LIBRARY.

A UDSF takes in a single row of data and returns a single value. These functions can be used anywhere a native Vertica function or statement can be used, except CREATE TABLE with its PARTITION BY or any segmentation clause.

CREATE FUNCTION automatically determines the function parameters and return value from data supplied by the factory class. Vertica supports overloading UDxs. When you call the function, Vertica passes the parameters to the function in the library to process.

Syntax

CREATE [ OR REPLACE ] FUNCTION [ IF NOT EXISTS ]
   [[database.]schema.]function AS
   [ LANGUAGE 'language' ]
   NAME 'factory'
   LIBRARY library
   [ FENCED | NOT FENCED ]

Arguments

OR REPLACE

If a function with the same name and arguments exists, replace it. You can use this to change between fenced and unfenced modes, for example. If you do not use this directive and the function already exists, the CREATE statement returns with a rollback error.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

IF NOT EXISTS

If a function with the same name and arguments exists, return without creating the function.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

[database.]schema

Database and schema. The default schema is public. If you specify a database, it must be the current database.

function

Name of the function to create. This is the name used in SQL invocations of the function. It does not need to match the name of the factory, but it is less confusing if they are the same or similar.

The function name must conform to the restrictions on Identifiers.

LANGUAGE 'language'

Language used to develop this function, one of the following:

• C++ (default)

• Python

• Java

• R

NAME 'factory'

Name of the factory class that generates the function instance.

LIBRARY library

Name of the C++ shared object file, Python file, Java Jar file, or R functions file. This library must already have been loaded by CREATE LIBRARY.

FENCED | NOT FENCED

Enables or disables fenced mode for this function. Functions written in Java and R always run in fenced mode.

Default: FENCED

Privileges

• CREATE privilege on the function's schema

• USAGE privilege on the function's library

Examples

The following example loads a library named ScalarFunctions and then defines a function named Add2ints that is mapped to the Add2intsInfo factory class in the library:

=> CREATE LIBRARY ScalarFunctions AS '/opt/vertica/sdk/examples/build/ScalarFunctions.so';
CREATE LIBRARY
=> CREATE FUNCTION Add2Ints AS LANGUAGE 'C++' NAME 'Add2IntsFactory' LIBRARY ScalarFunctions;
CREATE FUNCTION
=> \x
Expanded display is on.
=> SELECT * FROM USER_FUNCTIONS;

-[ RECORD 1 ]----------+----------------------------------------------------
schema_name            | public
function_name          | Add2Ints
procedure_type         | User Defined Function
function_return_type   | Integer
function_argument_type | Integer, Integer
function_definition    | Class 'Add2IntsFactory' in Library 'public.ScalarFunctions'
volatility             | volatile
is_strict              | f
is_fenced              | t
comment                |

=> \x
Expanded display is off.
=> -- Try a simple call to the function
=> SELECT Add2Ints(23,19);
 Add2Ints
----------
       42
(1 row)

The following example uses a scalar function that returns a ROW:

=> CREATE FUNCTION div_with_rem AS LANGUAGE 'C++' NAME 'DivFactory' LIBRARY ScalarFunctions;

=> SELECT div_with_rem(18,5);
        div_with_rem
------------------------------
 {"quotient":3,"remainder":3}
(1 row)

See also

5 - CREATE FUNCTION (SQL)

Stores SQL expressions as functions for use in queries. User-defined SQL functions are useful for executing complex queries and combining Vertica built-in functions. You simply call the function in a given query. If multiple SQL functions with the same name and argument types are in the search path, Vertica calls the first match that it finds.

SQL functions are flattened in all cases, including DDL.

Syntax

CREATE [ OR REPLACE ] FUNCTION [ IF NOT EXISTS ]
    [[database.]schema.]function( [ arg_list ] )
    RETURN return_type
    AS
    BEGIN
       RETURN expression;
    END;

Arguments

OR REPLACE

If a function of the same name and arguments exists, replace it. If you only change the function arguments, Vertica ignores this option and maintains both functions under the same name.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

IF NOT EXISTS

If a function with the same name and arguments exists, return without creating the function.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

[database.]schema

Database and schema. The default schema is public. If you specify a database, it must be the current database.

function

SQL function to create, where function conforms to conventions described in Identifiers.

arg_list

A comma-delimited list of argument names and their data types, specified in this format:

argname argtype[,...]

where:

• argname is the name of an argument passed to function.

• argtype is argname's data type.

return_type

The data type that this function returns.

RETURN expression

The SQL function body, where expression can contain built-in functions, operators, and argument names specified in the CREATE FUNCTION statement.

A semicolon at the end of the expression is required.

Note

CREATE FUNCTION allows only one RETURN expression. Return expressions do not support the following:

• FROM, WHERE, GROUP BY, ORDER BY, and LIMIT clauses

• Aggregation, analytics, and meta-functions

Privileges

Non-superuser:

• CREATE privilege on the function's schema

• USAGE privilege on the function's library

Strictness and volatility

Vertica infers the strictness and volatility (stable, immutable, or volatile) of a SQL function from its definition. Vertica then determines the correctness of usage, such as where an immutable function is expected but a volatile function is provided.

SQL functions and views

You can create views on the queries that use SQL functions and then query the views. When you create a view, a SQL function replaces a call to the user-defined function with the function body in a view definition. Therefore, when the body of the user-defined function is replaced, the view should also be replaced.

Examples

See Creating user-defined SQL functions.

See also

• ALTER FUNCTION (scalar)
• DROP FUNCTION
• User-defined SQL functions

6 - CREATE PARSER

Adds a user-defined load parser function to the catalog. The library containing the function must have been previously added using CREATE LIBRARY.

CREATE PARSER automatically determines the function parameters and return value from data supplied by the factory class. Vertica supports overloading load parser functions. When you call the SQL function, Vertica passes the input table to the function in the library to process.

Syntax

CREATE [ OR REPLACE ] PARSER [ IF NOT EXISTS ]
   [[database.]schema.]function AS
   [ LANGUAGE 'language' ]
   NAME 'factory'
   LIBRARY library
   [ FENCED | NOT FENCED ]

Arguments

OR REPLACE

If a function with the same name and arguments exists, replace it. You can use this to change between fenced and unfenced modes, for example. If you do not use this directive and the function already exists, the CREATE statement returns with a rollback error.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

IF NOT EXISTS

If a function with the same name and arguments exists, return without creating the function.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

[database.]schema

Database and schema. The default schema is public. If you specify a database, it must be the current database.

function

Name of the function to create. This is the name used in SQL invocations of the function. It does not need to match the name of the factory, but it is less confusing if they are the same or similar.

The function name must conform to the restrictions on Identifiers.

LANGUAGE 'language'

The language used to develop this function, one of the following:

• C++ (default)

• Java

• Python

NAME 'factory'

Name of the factory class that generates the function instance. This is the same name used by the RegisterFactory class.

LIBRARY library

Name of the C++ library shared object file, Python file, or Java Jar file. This library must already have been loaded by CREATE LIBRARY.

FENCED | NOT FENCED

Enables or disables fenced mode for this function.

Default: FENCED

Privileges

Superuser

Examples

The following example demonstrates loading a library named BasicIntegrerParserLib, then defining a parser function named BasicIntegerParser that is mapped to the BasicIntegerParserFactory factory class in the library:

=> CREATE LIBRARY BasicIntegerParserLib as '/opt/vertica/sdk/examples/build/BasicIntegerParser.so';
CREATE LIBRARY
=> CREATE PARSER BasicIntegerParser AS LANGUAGE 'C++' NAME 'BasicIntegerParserFactory' LIBRARY BasicIntegerParserLib;
CREATE PARSER FUNCTION
=> \x
Expanded display is on.
=> SELECT * FROM user_functions;
-[ RECORD 1 ]----------+--------------------
schema_name            | public
function_name          | BasicIntegerParser
procedure_type         | User Defined Parser
function_return_type   |
function_argument_type |
function_definition    |
volatility             |
is_strict              | f
is_fenced              | f
comment                |

See also

• DROP PARSER
• USER_FUNCTIONS
• User-defined load (UDL)

7 - CREATE SOURCE

Adds a user-defined load source function to the catalog. The library containing the function must have been previously added using CREATE LIBRARY.

CREATE SOURCE automatically determines the function parameters and return value from data supplied by the factory class. Vertica supports overloading load source functions. When you call the SQL function, Vertica passes the input table to the function in the library to process.

Syntax

CREATE [ OR REPLACE ] SOURCE [ IF NOT EXISTS ]
    [[database.]schema.]function AS
    [ LANGUAGE 'language' ]
    NAME 'factory'
    LIBRARY library
    [ FENCED | NOT FENCED ]

Arguments

OR REPLACE

If a function with the same name and arguments exists, replace it. You can use this to change between fenced and unfenced modes, for example. If you do not use this directive and the function already exists, the CREATE statement returns with a rollback error.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

IF NOT EXISTS

If a function with the same name and arguments exists, return without creating the function.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

[database.]schema

Database and schema. The default schema is public. If you specify a database, it must be the current database.

function

Name of the function to create. This is the name used in SQL invocations of the function. It does not need to match the name of the factory, but it is less confusing if they are the same or similar.

The function name must conform to the restrictions on Identifiers.

LANGUAGE 'language'

Language used to develop this function, one of the following:

• C++ (default)

• Java

NAME 'factory'

Name of the factory class that generates the function instance. This is the same name used by the RegisterFactory class.

LIBRARY library

Name of the C++ library shared object file or Java Jar file. This library must already have been loaded by CREATE LIBRARY.

FENCED | NOT FENCED

Enables or disables fenced mode for this function.

**Default: **FENCED

Privileges

Superuser

Examples

The following example demonstrates loading a library named curllib, then defining a source function named curl that is mapped to the CurlSourceFactory factory class in the library:

=> CREATE LIBRARY curllib as '/opt/vertica/sdk/examples/build/cURLLib.so';
CREATE LIBRARY
=> CREATE SOURCE curl AS LANGUAGE 'C++' NAME 'CurlSourceFactory' LIBRARY curllib;
CREATE SOURCE
=> \x
Expanded display is on.
=> SELECT * FROM user_functions;
-[ RECORD 1 ]----------+--------------------
schema_name            | public
function_name          | curl
procedure_type         | User Defined Source
function_return_type   |
function_argument_type |
function_definition    |
volatility             |
is_strict              | f
is_fenced              | f
comment                |

See also

• DROP SOURCE
• USER_FUNCTIONS
• User-defined load (UDL)

8 - CREATE TRANSFORM FUNCTION

Adds a user-defined transform function (UDTF) to the catalog. The library containing the function must have been previously added using CREATE LIBRARY.

CREATE TRANSFORM FUNCTION automatically determines the function parameters and return value from data supplied by the factory class. Vertica supports overloading transform functions. When you call the SQL function, Vertica passes the input table to the transform function in the library to process.

Syntax

CREATE [ OR REPLACE ] TRANSFORM FUNCTION [ IF NOT EXISTS ]
    [[database.]schema.]function AS
    [ LANGUAGE 'language' ]
    NAME 'factory'
    LIBRARY library
    [ FENCED | NOT FENCED ]

Arguments

OR REPLACE

If a function with the same name and arguments exists, replace it. You can use this to change between fenced and unfenced modes, for example. If you do not use this directive and the function already exists, the CREATE statement returns with a rollback error.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

IF NOT EXISTS

If a function with the same name and arguments exists, return without creating the function.

OR REPLACE and IF NOT EXISTS are mutually exclusive.

[database.]schema

Database and schema. The default schema is public. If you specify a database, it must be the current database.

function

Name of the function to create. This is the name used in SQL invocations of the function. It does not need to match the name of the factory, but it is less confusing if they are the same or similar.

The function name must conform to the restrictions on Identifiers.

LANGUAGE 'language'

The language used to develop this function, one of the following:

• C++ (default)

• Java

• R

• Python

NAME 'factory'

Name of the factory class that generates the function instance.

LIBRARY library

Name of the C++ shared object file, Python file, Java Jar file, or R functions file. This library must already have been loaded by CREATE LIBRARY.

FENCED | NOT FENCED

Enables or disables fenced mode for this function. Functions written in Java and R always run in fenced mode.

Default: FENCED

Privileges

Non-superuser:

• CREATE privilege on the function's schema

• USAGE privilege on the function's library

Restrictions

A query that includes a UDTF cannot:

• Include statements other than the SELECT statement that calls the UDTF and a PARTITION BY expression unless the UDTF is marked as a one-to-many UDTF

• Call an analytic function

• Call another UDTF

• Include one of the following clauses:

  • TIMESERIES

  • Pattern matching

  • Gap filling and interpolation

Examples

The following example loads a library named TransformFunctions and then defines a function named tokenize that is mapped to the TokenFactory factory class in the library:

=> CREATE LIBRARY TransformFunctions AS
   '/home/dbadmin/TransformFunctions.so';
CREATE LIBRARY
=> CREATE TRANSFORM FUNCTION tokenize
   AS LANGUAGE 'C++' NAME 'TokenFactory' LIBRARY TransformFunctions;
CREATE TRANSFORM FUNCTION

See also

• DROP FUNCTION
• Developing user-defined extensions (UDxs)