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ALTER FUNCTION(7)                SQL Commands                ALTER FUNCTION(7)



NAME
       ALTER FUNCTION - change the definition of a function


SYNOPSIS
       ALTER FUNCTION name ( [ [ argmode ] [ argname ] argtype [, ...] ] )
           action [ ... ] [ RESTRICT ]
       ALTER FUNCTION name ( [ [ argmode ] [ argname ] argtype [, ...] ] )
           RENAME TO new_name
       ALTER FUNCTION name ( [ [ argmode ] [ argname ] argtype [, ...] ] )
           OWNER TO new_owner
       ALTER FUNCTION name ( [ [ argmode ] [ argname ] argtype [, ...] ] )
           SET SCHEMA new_schema

       where action is one of:

           CALLED ON NULL INPUT | RETURNS NULL ON NULL INPUT | STRICT
           IMMUTABLE | STABLE | VOLATILE
           [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER
           COST execution_cost
           ROWS result_rows
           SET configuration_parameter { TO | = } { value | DEFAULT }
           SET configuration_parameter FROM CURRENT
           RESET configuration_parameter
           RESET ALL


DESCRIPTION
       ALTER FUNCTION changes the definition of a function.

       You  must  own  the  function  to use ALTER FUNCTION.  To change a function's schema, you must also have CREATE
       privilege on the new schema.  To alter the owner, you must also be a direct or indirect member of the new  own-
       ing  role,  and that role must have CREATE privilege on the function's schema. (These restrictions enforce that
       altering the owner doesn't do anything you couldn't do by dropping and recreating  the  function.   However,  a
       superuser can alter ownership of any function anyway.)

PARAMETERS
       name   The name (optionally schema-qualified) of an existing function.

       argmode
              The  mode  of an argument: IN, OUT, INOUT, or VARIADIC.  If omitted, the default is IN.  Note that ALTER
              FUNCTION does not actually pay any attention to OUT arguments, since only the input arguments are needed
              to  determine  the  function's  identity.  So it is sufficient to list the IN, INOUT, and VARIADIC argu-
              ments.

       argname
              The name of an argument.  Note that ALTER FUNCTION does not  actually  pay  any  attention  to  argument
              names, since only the argument data types are needed to determine the function's identity.

       argtype
              The data type(s) of the function's arguments (optionally schema-qualified), if any.

       new_name
              The new name of the function.

       new_owner
              The  new  owner  of  the  function. Note that if the function is marked SECURITY DEFINER, it will subse-
              quently execute as the new owner.

       new_schema
              The new schema for the function.

       CALLED ON NULL INPUT

       RETURNS NULL ON NULL INPUT

       STRICT CALLED ON NULL INPUT changes the function so that it will be invoked when some or all of  its  arguments
              are  null. RETURNS NULL ON NULL INPUT or STRICT changes the function so that it is not invoked if any of
              its arguments are null; instead, a null result is  assumed  automatically.  See  CREATE  FUNCTION  [cre-
              ate_function(7)] for more information.

       IMMUTABLE

       STABLE

       VOLATILE
              Change  the  volatility  of  the  function  to the specified setting.  See CREATE FUNCTION [create_func-
              tion(7)] for details.

       [ EXTERNAL ] SECURITY INVOKER

       [ EXTERNAL ] SECURITY DEFINER
              Change whether the function is a security definer or not. The key word EXTERNAL is ignored for SQL  con-
              formance. See CREATE FUNCTION [create_function(7)] for more information about this capability.

       COST execution_cost
              Change  the estimated execution cost of the function.  See CREATE FUNCTION [create_function(7)] for more
              information.

       ROWS result_rows
              Change the estimated number of rows returned by a set-returning  function.  See  CREATE  FUNCTION  [cre-
              ate_function(7)] for more information.

       configuration_parameter

       value  Add  or  change  the  assignment to be made to a configuration parameter when the function is called. If
              value is DEFAULT or, equivalently, RESET is used, the function-local setting is  removed,  so  that  the
              function  executes  with the value present in its environment. Use RESET ALL to clear all function-local
              settings.  SET FROM CURRENT saves the session's current value of  the  parameter  as  the  value  to  be
              applied when the function is entered.

              See SET [set(7)] and in the documentation for more information about allowed parameter names and values.

       RESTRICT
              Ignored for conformance with the SQL standard.

EXAMPLES
       To rename the function sqrt for type integer to square_root:

       ALTER FUNCTION sqrt(integer) RENAME TO square_root;


       To change the owner of the function sqrt for type integer to joe:

       ALTER FUNCTION sqrt(integer) OWNER TO joe;


       To change the schema of the function sqrt for type integer to maths:

       ALTER FUNCTION sqrt(integer) SET SCHEMA maths;


       To adjust the search path that is automatically set for a function:

       ALTER FUNCTION check_password(text) SET search_path = admin, pg_temp;


       To disable automatic setting of search_path for a function:

       ALTER FUNCTION check_password(text) RESET search_path;

       The function will now execute with whatever search path is used by its caller.

COMPATIBILITY
       This statement is partially compatible with the ALTER FUNCTION statement in  the  SQL  standard.  The  standard
       allows  more  properties  of  a function to be modified, but does not provide the ability to rename a function,
       make a function a security definer, attach configuration parameter values to a function, or change  the  owner,
       schema,  or  volatility  of  a function. The standard also requires the RESTRICT key word, which is optional in
       PostgreSQL.

SEE ALSO
       CREATE FUNCTION [create_function(7)], DROP FUNCTION [drop_function(7)]



SQL - Language Statements         2014-02-17                 ALTER FUNCTION(7)