ALTER FUNCTION()		 SQL Commands		      ALTER FUNCTION()



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(7) for more infor-
	      mation.

       IMMUTABLE

       STABLE

       VOLATILE
	      Change  the volatility of the function to the specified setting.
	      See create_function(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 conformance. See cre-
	      ate_function(7) 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(7)], DROP FUNCTION [drop_function(l)]



SQL - Language Statements	  2010-12-14		      ALTER FUNCTION()