ALTER FUNCTION
Section: PostgreSQL 15.6 Documentation (7)
Updated: 2024
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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 | 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 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. 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
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.
PARALLEL
-
Change whether the function is deemed safe for parallelism. See
CREATE FUNCTION (CREATE_FUNCTION(7))
for details.
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.
SUPPORT support_function
-
Set or change the planner support function to use for this function. See
Section 38.11
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
SET(7)
and
Chapter 20
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
CREATE FUNCTION (CREATE_FUNCTION(7)), DROP FUNCTION (DROP_FUNCTION(7)), ALTER PROCEDURE (ALTER_PROCEDURE(7)), ALTER ROUTINE (ALTER_ROUTINE(7))
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- PARAMETERS
-
- EXAMPLES
-
- COMPATIBILITY
-
- SEE ALSO
-
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Time: 23:55:32 GMT, March 28, 2024