ALTER DATABASE

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Contents

名字

ALTER DATABASE -- change a database

语法概要
ALTER DATABASE name [ [ WITH ] option [ ... ] ]

where option can be:

    CONNECTION LIMIT connlimit

ALTER DATABASE name RENAME TO new_name

ALTER DATABASE name OWNER TO new_owner

ALTER DATABASE name SET TABLESPACE new_tablespace

ALTER DATABASE name SET configuration_parameter { TO | = } { value | DEFAULT }
ALTER DATABASE name SET configuration_parameter FROM CURRENT
ALTER DATABASE name RESET configuration_parameter
ALTER DATABASE name RESET ALL
描述

ALTER DATABASE changes the attributes of a database.

The first form changes certain per-database settings. (See below for details.) Only the database owner or a superuser can change these settings.

The second form changes the name of the database. Only the database owner or a superuser can rename a database; non-superuser owners must also have the CREATEDB privilege. The current database cannot be renamed. (Connect to a different database if you need to do that.)

The third form changes the owner of the database. To alter the owner, you must own the database and also be a direct or indirect member of the new owning role, and you must have the CREATEDB privilege. (Note that superusers have all these privileges automatically.)

The fourth form changes the default tablespace of the database. Only the database owner or a superuser can do this; you must also have create privilege for the new tablespace. This command physically moves any tables or indexes in the database's old default tablespace to the new tablespace. Note that tables and indexes in non-default tablespaces are not affected.

The remaining forms change the session default for a run-time configuration variable for a PostgreSQL database. Whenever a new session is subsequently started in that database, the specified value becomes the session default value. The database-specific default overrides whatever setting is present in postgresql.conf or has been received from the postgres command line. Only the database owner or a superuser can change the session defaults for a database. Certain variables cannot be set this way, or can only be set by a superuser.

参数

name The name of the database whose attributes are to be altered.

connlimit How many concurrent connections can be made to this database. -1 means no limit.

new_name The new name of the database.

new_owner The new owner of the database.

new_tablespace The new default tablespace of the database.

configuration_parameter value Set this database's session default for the specified configuration parameter to the given value. If value is DEFAULT or, equivalently, RESET is used, the database-specific setting is removed, so the system-wide default setting will be inherited in new sessions. Use RESET ALL to clear all database-specific settings. SET FROM CURRENT saves the session's current value of the parameter as the database-specific value.

See SET and Chapter 18 for more information about allowed parameter names and values.

注意

It is also possible to tie a session default to a specific role rather than to a database; see ALTER ROLE. Role-specific settings override database-specific ones if there is a conflict.

示例

To disable index scans by default in the database test:

ALTER DATABASE test SET enable_indexscan TO off; Compatibility

The ALTER DATABASE statement is a PostgreSQL extension.

参见

CREATE DATABASE, DROP DATABASE, SET, CREATE TABLESPACE

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