How to Quiesce a Database

By Alexander Geldutes

Quiesce a database is a new feature in Oracle 9i.It is similar to the restricted mode.When a database in a quiesced mode no one can connect to the database except SYS and SYSTEM and all current user sessions are suspended.As the result in the quiesced mode DBA can perform. some maintenance task.

In order to quiesce a database（oracle versions above 9i ）:
Set the RESOURCE_MANAGER_PLAN parameter to a non-null value.
alter system set resource_manager_plan='SYSPLAN'scope=both;

（oracle versions above 10g ）

SQL>conn / as sysdba

Connected.

SQL> alter system quiesce restricted;

System altered.
SQL> select status,active_state from v$instance;

STATUS       ACTIVE_ST
------------     ---------
OPEN         QUIESCED

To bring a database back in the fully operational mode, usethe following command:

SQL>alter system unquiesce;

System altered.

SQL>select active_state from v$instance;

ACTIVE_ST
---------
NORMAL
（oracle system Default）