ALTER DATABASE

Modify the properties of the database

Summary

ALTER DATABASE name [ WITH CONNECTION LIMIT connlimit ]

ALTER DATABASE name RENAME TO newname

ALTER DATABASE name OWNER TO new_owner

ALTER DATABASE name SET TABLESPACE new_tablespace

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

describe

ALTER DATABASE Modify the properties of a database.

The first statement changes the number of connections to the database. Only the owner or superuser of the data can change this setting.

The second statement changes the name of the database. Only the database owner or superuser can rename the database; non-superusers must have CREATEDB permissions. You cannot modify the name of the current database and connect to another database first.

The third gathers the owner of the modified database. To modify the owner, you must be a direct or indirect member of the new role, and you must have CREATEDB permissions. (Super users can automatically have all permissions.)

The fourth statement changes the default tablespace of the database. Only the database owner or superuser can modify the default table empty, and you also need to have the permission to create on the new tablespace. This command will move all tables and indexes in the default tablespace of this database to the new tablespace. Note that tables and indexes not in the default tablespace are not affected.

The remaining statements are used to modify the default values of the YMatrix database session level parameter. When a session is opened in the database, the parameter value provided by this session will become the default parameter value. The default value of the database configuration in the configuration file (postgresql.conf) will be overwritten. Only the database owner or superuser can modify the session default value. Some parameters cannot be set in this way, or can only be set by superusers.

Parameters

name

The database name of the property to be modified.

connlimit

Maximum number of concurrent connections. Default value -1 means no limit

parameter value

Sets the session default value of the database that specifies configuration parameters to the given value. If this value is DEFAULT, or equivalent RESET, the specific settings of the database will be deleted, so the system-wide default settings will be inherited in the new session. Use RESET ALL to clear all database settings.

newname

New database name.

new_owner

New database owner.

new_tablespace

New database default tablespace.

Notice

You can also set configuration parameter session default values for specific roles (users) instead of databases. If there is a conflict, role-specific settings override database-specific settings. See ALTER ROLE.

Example

Set the default schema search path for the database mydatabase:

ALTER DATABASE mydatabase SET search_path TO myschema, 
public, pg_catalog;

compatibility

The ALTER DATABASE statement is an extension statement of YMatrix.