Pages

Saturday, August 27, 2011

11g Snapshot Standby Database


A snapshot standby database is a temporarily opened real time production database for testing or reporting. It is a fully updateable standby database after conversion from physical standby. It receives redo data from primary, but does not apply. The redo data is applied after conversion back to physical standby to sync up with primary. It implicitly creates a guaranteed restore point during the conversion to snapshot standby and removes this guaranteed restore point during the conversion back to physical standby.

CONVERT TO SNAPSHOT STANDBY
1. Stop Redo Apply
SQL> recover managed standby database cancel;
2. Ensure the database is mounted, but not open.
3. Convert to Snapshot Standby. This creates the GRP and leaves the database in nomount mode.
SQL> alter database convert to snapshot standby.
4. Restart the database.
SQL> shutdown immediate
SQL> startup

CONVERT BACK TO PHYSICAL STANDBY
1.  Ensure the database is mounted, but not open.
SQL> shutdown immediate
SQL> startup mount
2. Convert to Physical Standby. This discards the changes made to the database, flashback the database to GRP, deletes the flashback logs in recovery area, drops GRP and leaves the database in nomount mode.
SQL> alter database convert to physical standby;
3. Restart the database in mount mode.
SQL> shutdown immediate
SQL> startup mount
4. Start Redo Apply.
SQL> recover managed standby database disconnect from session;


No comments:

Post a Comment