Postgresql 中文操作指南

ALTER DATABASE

ALTER DATABASE — 更改数据库

ALTER DATABASE — change a database

Synopsis

ALTER DATABASE name [ [ WITH ] option [ ... ] ]

where option can be:

    ALLOW_CONNECTIONS allowconn
    CONNECTION LIMIT connlimit
    IS_TEMPLATE istemplate

ALTER DATABASE name RENAME TO new_name

ALTER DATABASE name OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }

ALTER DATABASE name SET TABLESPACE new_tablespace

ALTER DATABASE name REFRESH COLLATION VERSION

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

Description

ALTER DATABASE 更改数据库的属性。

ALTER DATABASE changes the attributes of a database.

第一种形式更改特定于データベース的某些设置。（请参见以下内容以了解详细信息。）只有数据库所有者或超级用户才能更改这些设置。

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

第二种形式更改数据库的名称。只有数据库所有者或者超级用户才能重命名数据库；非超级用户所有者还必须具有 CREATEDB 权限。当前数据库不能重命名。（如果你需要执行操作，请连接到其他数据库。）

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.)

第三种形式更改数据库的所有者。要更改所有者，你必须具有 SET ROLE 的权限才能使用新的所有者角色，而且你必须具有 CREATEDB 权限。（请注意，超级用户自动拥有所有这些权限。）

The third form changes the owner of the database. To alter the owner, you must be able to SET ROLE to the new owning role, and you must have the CREATEDB privilege. (Note that superusers have all these privileges automatically.)

第四种形式更改数据库的默认表空间。只有数据库所有者或超级用户才能执行此操作；你还必须具有新表空间的创建权限。此命令将在数据库旧默认表空间中物理移动所有表或索引到新的表空间。此数据库的新默认表空间必须为空，并且任何人都不可以连接到该数据库。不受默认表空间影响的表和索引。

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. The new default tablespace must be empty for this database, and no one can be connected to the database. Tables and indexes in non-default tablespaces are unaffected.

剩余形式会更改 PostgreSQL 数据库的运行时配置变量的会话默认值。每当随后在新会话中启动会话，指定的变量就成为会话的默认值。数据库特定默认值会覆盖在 postgresql.conf 中存在的设置，或者从 postgres 命令行中接收到的设置。只有数据库所有者或超级用户才能更改数据库的会话默认值。某些变量不能以这种方式设置，或者只能由超级用户设置。

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.

Parameters

  • name

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

  • allowconn

    • If false then no one can connect to this database.

  • connlimit

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

  • istemplate

    • If true, then this database can be cloned by any user with CREATEDB privileges; if false, then only superusers or the owner of the database can clone it.

  • 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.

    • This form of the command cannot be executed inside a transaction block.

  • REFRESH COLLATION VERSION

    • Update the database collation version. See Notes for background.

  • 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 20 for more information about allowed parameter names and values.

Notes

也可以将会话默认设置绑定到特定角色，而不是数据库；请参见 ALTER ROLE 。如果出现冲突，特定于角色的设置将覆盖特定于数据库的设置。

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.

Examples

要在数据库 test 中默认禁用索引扫描：

To disable index scans by default in the database test:

ALTER DATABASE test SET enable_indexscan TO off;

Compatibility

ALTER DATABASE 语句是 PostgreSQL 扩展。

The ALTER DATABASE statement is a PostgreSQL extension.

See Also

CREATE DATABASE ， DROP DATABASE ， SET ， CREATE TABLESPACE

CREATE DATABASE, DROP DATABASE, SET, CREATE TABLESPACE