In normal situation, DBA can use Data Guard utility to switchover or failover database roles. DBA can also use SQL command to switchover or failver database roles.
This post demonstrate how to failover to standby database in 12c when Primary Databases is lost due to various reasons.
Check Database Role
SQL> SELECT OPEN_MODE,PROTECTION_MODE,DATABASE_ROLE FROM V$DATABASE; OPEN_MODE PROTECTION_MODE DATABASE_ROLE -------------------- -------------------- ---------------- MOUNTED MAXIMUM PERFORMANCE PHYSICAL STANDBY
Stop Standby Database Recovery
SQL> alter database recover managed standby database cancel; Database altered.
Complete Recovery and Transit Current Standby as Primary
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE FINISH; Database altered.
After this command, this standby database will NOT be able to go back to standby database any more.
Activate the Standby Database
SQL>alter database activate standby database; Database altered.
Open the Database
SQL>alter database open; SQL> SELECT OPEN_MODE,PROTECTION_MODE,DATABASE_ROLE FROM V$DATABASE; OPEN_MODE PROTECTION_MODE DATABASE_ROLE ---------- -------------------- ---------------- MOUNTED MAXIMUM PERFORMANCE PRIMARY
The Last and Not the Least
- Backup new primary database ASAP.
- Reinstate the old primary as new standby database, if flashback on. Otherwise rebuild the standby database as per normal processes.
Make DBA Life Easy 