alter_function(5)

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

DESCRIPTION

       ALTER FUNCTION changes the definition of a function.

       You  must  own  the  function to use ALTER FUNCTION.  To change a func-
       tion'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 owning role, and that role must have CREATE privilege on the  func-
       tion'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: either IN, OUT, or INOUT. If omitted,
              the default is IN.  Note that ALTER FUNCTION does  not  actually
              pay  any  attention to OUT arguments, since only the input argu-
              ments are needed to determine the function's identity.  So it is
              sufficient to list the IN and INOUT arguments.

       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 iden-
              tity.

       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 subsequently 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 [create_func-
              tion(5)] for more information.

       IMMUTABLE

       STABLE

       VOLATILE
              Change the volatility of the function to the specified  setting.
              See CREATE FUNCTION [create_function(5)] 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  conformance.  See  CREATE
              FUNCTION  [create_function(5)]  for  more information about this
              capability.

       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;

COMPATIBILITY

       This statement is partially compatible with the ALTER  FUNCTION  state-
       ment  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, 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(5)], DROP FUNCTION [drop_function(l)]

SQL - Language Statements         2008-06-08                  ALTER FUNCTION()