In that configuration, you must define
the LOG_ARCHIVE_DEST_n parameters to allow those standby sites to receive data from the new
primary database location.
NOTE
Verify that the database that will become the new primary database is
running in ARCHIVELOG mode.
In the following sections, you will see the steps required to perform a switchover to a standby
database. The standby database should be actively applying redo log data prior to the switchover,
as this will minimize the time required to complete the switchover.
Switchovers to Physical Standby Databases
Switchovers are initiated on the primary database and completed on the standby database. In this
section, you will see the steps for performing a switchover to a physical standby database. There
is no data loss during a switchover.
Begin by verifying that the primary database is capable of performing a switchover. Query
V$DATABASE for the value of the SWITCHOVER_STATUS column:
select switchover_status from v$database;
488 Oracle Database 11g DBA Handbook
If the SWITCHOVER_STATUS column??™s value is anything other than TO STANDBY, it is not
possible to perform the switchover (usually due to a configuration or hardware issue). If the
column??™s value is SESSIONS ACTIVE, you should terminate active user sessions. Valid values for
the Switchover_Status column are shown in Table 13-2.
From within the primary database, you can initiate its transition to the physical standby
database role with the following command:
alter database commit to switchover to physical standby;
As part of executing this command, Oracle will back up the current primary database??™s
controlfile to a trace file.
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