Once the standby database is setup using Data Guard and works properly, you may want to test switchover, or perform switchover to reduce primary database downtime during OS upgrades or hardware upgrades. (To set up a Physical Standby database, please refer to my OraFAQ blog “Oracle 10g – Manually Create a Physical Standby Database Using Data Guard”.)
A switchover allows the primary database to switch roles with its standby database. There is no data loss during a switchover. You can switch back to the original Primary database later by performing another switchover.
