ALTER FUNCTION
ALTER FUNCTION
7
SQL - Language Statements
ALTER FUNCTION
change the definition of a function
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 | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER FUNCTION name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]
SET SCHEMA new_schema
ALTER FUNCTION name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]
[ NO ] DEPENDS ON EXTENSION extension_name
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
PARALLEL { UNSAFE | RESTRICTED | SAFE }
COST execution_cost
ROWS result_rows
SUPPORT support_function
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 be able to
SET ROLE to 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. If no
argument list is specified, the name must be unique in its schema.
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.
DEPENDS ON EXTENSION extension_name
NO DEPENDS ON EXTENSION extension_name
This form marks the function as dependent on the extension, or no longer
dependent on that extension if NO is specified.
A function that's marked as dependent on an extension is dropped when the
extension is dropped, even if CASCADE is not specified.
A function can depend upon multiple extensions, and will be dropped when
any one of those extensions is dropped.
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
for more information.
IMMUTABLE
STABLE
VOLATILE
Change the volatility of the function to the specified setting.
See 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 for more information about
this capability.
PARALLEL
Change whether the function is deemed safe for parallelism.
See for details.
LEAKPROOF
Change whether the function is considered leakproof or not.
See for more information about
this capability.
COST execution_cost
Change the estimated execution cost of the function.
See for more information.
ROWS result_rows
Change the estimated number of rows returned by a set-returning
function. See for more information.
SUPPORT support_function
Set or change the planner support function to use for this function.
See for details. You must be
superuser to use this option.
This option cannot be used to remove the support function altogether,
since it must name a new support function. Use CREATE OR
REPLACE FUNCTION if you need to do that.
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 and
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 mark the function sqrt for type
integer as being dependent on the extension
mathlib:
ALTER FUNCTION sqrt(integer) DEPENDS ON EXTENSION mathlib;
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