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27.12.21.8 The user_defined_functions Table

The user_defined_functions table contains a row for each user-defined function (UDF) registered automatically by a component or plugin, or manually by a CREATE FUNCTION statement. For information about operations that add or remove table rows, see Section 5.7.1, “Installing and Uninstalling User-Defined Functions”.

The user_defined_functions table has these columns:

  • UDF_NAME

    The UDF name as referred to in SQL statements. The value is NULL if the function was registered by a CREATE FUNCTION statement and is in the process of unloading.

  • UDF_RETURN_TYPE

    The UDF return value type. The value is one of int, decimal, real, char, or row.

  • UDF_TYPE

    The UDF type. The value is one of function (scalar) or aggregate.

  • UDF_LIBRARY

    The name of the library file containing the executable UDF code. The file is located in the directory named by the plugin_dir system variable. The value is NULL if the UDF was registered by a component or plugin rather than by a CREATE FUNCTION statement.

  • UDF_USAGE_COUNT

    The current UDF usage count. This is used to tell whether statements currently are accessing the UDF.

The user_defined_functions table has these indexes:

  • Primary key on (UDF_NAME)

TRUNCATE TABLE is not permitted for the user_defined_functions table.