| ALTER_FUNCTION(7) - phpMan
ALTER FUNCTION(7) PostgreSQL 12.3 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 | CURRENT_USER | SESSION_USER }
ALTER FUNCTION name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]
SET SCHEMA new_schema
ALTER FUNCTION name [ ( [ [ argmode ] [ argname ] argtype [, ...] ] ) ]
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.
extension_name
The name of the extension that the function is to depend on.
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 37.11
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 19 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))
PostgreSQL 12.3 2020 ALTER FUNCTION(7)
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