简体中文

DROP AGGREGATE

Removes an aggregate function.

Synopsis

DROP AGGREGATE [IF EXISTS] <name> ( <aggregate_signature> ) [, ...] [CASCADE | RESTRICT]

where <aggregate_signature> is:

* |
[ <argmode> ] [ <argname> ] <argtype> [ , ... ] |
[ [ <argmode> ] [ <argname> ] <argtype> [ , ... ] ] ORDER BY [ <argmode> ] [ <argname> ] <argtype> [ , ... ]
Description
DROP AGGREGATE removes an existing aggregate function. To run this command the current user must be the owner of the aggregate function.

Parameters

IF EXISTS
- Do not throw an error if the aggregate does not exist. A notice is issued in this case.
name
- The name (optionally schema-qualified) of an existing aggregate function.
argmode
- The mode of an argument: IN or VARIADIC. If omitted, the default is IN.
argname
- The name of an argument. Note that DROP AGGREGATE does not actually pay any attention to argument names, since only the argument data types are needed to determine the aggregate function's identity.
argtype
- An input data type on which the aggregate function operates. To reference a zero-argument aggregate function, write * in place of the list of argument specifications. To reference an ordered-set aggregate function, write ORDER BY between the direct and aggregated argument specifications.
CASCADE
- Automatically drop objects that depend on the aggregate function (such as views using it) and in turn all objects that depend on those objects.
RESTRICT
- Refuse to drop the aggregate function if any objects depend on it. This is the default.

Notes

Alternative syntaxes for referencing ordered-set aggregates are described under ALTER AGGREGATE.

Examples

To remove the aggregate function myavg for type integer:

DROP AGGREGATE myavg(integer);

To remove the hypothetical-set aggregate function myrank, which takes an arbitrary list of ordering columns and a matching list of direct arguments:

DROP AGGREGATE myrank(VARIADIC "any" ORDER BY VARIADIC "any");

To remove multiple aggregate functions in one command:

DROP AGGREGATE myavg(integer), myavg(bigint);

Compatibility

There is no DROP AGGREGATE statement in the SQL standard.