ALTER FUNCTION — change the definition of a function
ALTER FUNCTIONname
( [type
[, ...] ] )action
[, ... ] [ RESTRICT ] ALTER FUNCTIONname
( [type
[, ...] ] ) RENAME TOnewname
ALTER FUNCTIONname
( [type
[, ...] ] ) OWNER TOnewowner
whereaction
is one of: CALLED ON NULL INPUT | RETURNS NULL ON NULL INPUT | STRICT IMMUTABLE | STABLE | VOLATILE [ EXTERNAL ] SECURITY INVOKER | [ EXTERNAL ] SECURITY DEFINER
name
The name (optionally schema-qualified) of an existing function.
type
The data type of an argument of the function.
newname
The new name of the function.
newowner
The new owner of the function. To change the owner of a
function, you must be a superuser. Note that if the function is
marked SECURITY DEFINER
, it will subsequently
execute as the new owner.
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
always returns null if any of its arguments are null. See CREATE FUNCTION for more information.
IMMUTABLE
STABLE
VOLATILE
Change the volatility of the function to the specified type. See CREATE FUNCTION for more information about function volatility.
[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 for more
information about this capability.
RESTRICT
Ignored for conformance with the SQL standard.
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;
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,
or change the owner or volatility of a function. The standard also
requires the RESTRICT
key word; it is optional in
PostgreSQL.