ALTER FUNCTION(7)	PostgreSQL 9.2.24 Documentation	     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 | [ NOT ] LEAKPROOF
	   [ 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
       owning 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 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 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 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_FUNCTION(7)) for
	   more information.

       IMMUTABLE, STABLE, VOLATILE
	   Change the volatility of the function to the specified setting. See
	   CREATE FUNCTION (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 CREATE FUNCTION
	   (CREATE_FUNCTION(7)) for more information about this capability.

       LEAKPROOF
	   Change whether the function is considered leakproof or not. 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 (CREATE_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 value of the parameter that is current
	   when ALTER FUNCTION is executed as the value to be applied when the
	   function is entered.

	   See SET(7) and Chapter 18, Server Configuration, 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))



PostgreSQL 9.2.24		  2017-11-06		     ALTER FUNCTION(7)