Postgresql 中文操作指南

ALTER AGGREGATE

ALTER AGGREGATE - 更改聚合函数的定义

ALTER AGGREGATE — change the definition of an aggregate function

Synopsis

ALTER AGGREGATE name ( aggregate_signature ) RENAME TO new_name
ALTER AGGREGATE name ( aggregate_signature )
                OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }
ALTER AGGREGATE name ( aggregate_signature ) SET SCHEMA new_schema

where aggregate_signature is:

* |
[ argmode ] [ argname ] argtype [ , ... ] |
[ [ argmode ] [ argname ] argtype [ , ... ] ] ORDER BY [ argmode ] [ argname ] argtype [ , ... ]

Description

ALTER AGGREGATE 更改聚合函数的定义。

ALTER AGGREGATE changes the definition of an aggregate function.

你必须拥有聚合函数才能使用 ALTER AGGREGATE 。要更改聚合函数的模式,你还必须对新模式拥有 CREATE 权限。要更改所有者,你必须能够 SET ROLE 为新的拥有者角色,且该角色必须对聚合函数的模式具有 CREATE 权限。(这些限制强制执行更改所有者不会做出无法通过舍弃和重新创建聚合函数来完成的任何操作。但是,超级用户可以更改任何聚合函数的所有权。)

You must own the aggregate function to use ALTER AGGREGATE. To change the schema of an aggregate function, 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 aggregate function’s schema. (These restrictions enforce that altering the owner doesn’t do anything you couldn’t do by dropping and recreating the aggregate function. However, a superuser can alter ownership of any aggregate function anyway.)

Parameters

  • 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 ALTER 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.

  • new_name

    • The new name of the aggregate function.

  • new_owner

    • The new owner of the aggregate function.

  • new_schema

    • The new schema for the aggregate function.

Notes

引用有序集合聚合的建议语法是在直接参数和聚合参数规范之间编写 ORDER BY ,其样式与 CREATE AGGREGATE 中的相同。然而,它也将省略 ORDER BY 并仅将直接参数和聚合参数规范运行到单个列表中。在此缩写形式中,如果在直接和聚合参数列表中都使用了 VARIADIC "any" ,那么只编写一次 VARIADIC "any"

The recommended syntax for referencing an ordered-set aggregate is to write ORDER BY between the direct and aggregated argument specifications, in the same style as in CREATE AGGREGATE. However, it will also work to omit ORDER BY and just run the direct and aggregated argument specifications into a single list. In this abbreviated form, if VARIADIC "any" was used in both the direct and aggregated argument lists, write VARIADIC "any" only once.

Examples

要为类型 integer 重命名聚合函数 myavgmy_average

To rename the aggregate function myavg for type integer to my_average:

ALTER AGGREGATE myavg(integer) RENAME TO my_average;

要将类型 integer 的聚合函数 myavg 的所有者更改为 joe

To change the owner of the aggregate function myavg for type integer to joe:

ALTER AGGREGATE myavg(integer) OWNER TO joe;

要将直接参数类型为 float8 、聚合参数类型为 integer 的有序集合聚合 mypercentile 移动到模式 myschema

To move the ordered-set aggregate mypercentile with direct argument of type float8 and aggregated argument of type integer into schema myschema:

ALTER AGGREGATE mypercentile(float8 ORDER BY integer) SET SCHEMA myschema;

此操作也可用:

This will work too:

ALTER AGGREGATE mypercentile(float8, integer) SET SCHEMA myschema;

Compatibility

SQL 标准中没有 ALTER AGGREGATE 语句。

There is no ALTER AGGREGATE statement in the SQL standard.