Oracle Snapshot Standby

MarkBurgessMark Burgess  |  

What is Oracle Dataguard Snapshot Standby?

Oracle Data Guard Snapshot Standby allows you to open an Oracle Data Guard physical standby database for read/write access. Whilst you can replicate this functionality from Oracle 10g by using a combination of flashback database and manually running the required commands, Snapshot Standby offers a far more simple approach.

Snapshot Standby simplifies the whole process by reducing the number of commands required to open a physical standby for read/write access, and then converting it back to being a standby. The conversion from standby to “primary” is completed along with enabling flashback database and creating a restore point.

Snapshot Standby allows for Log Transport to continue sending redo data from the primary whilst the Snapshot Standby database open. This is a major advantage over using manual flashback as you avoid impacting your RPO during DR testing.

Example

1. Cancel media recovery on the standby:

alter database recover managed standby cancel;

2. Convert and Open

alter database recover managed standby database cancel;
alter database flashback on;
alter database convert to snapshot standby;
shutdown immediate;
startup;

No you can use the snapshot database as an exact copy of production. When finished you need to convert the snapshot standby back to a physical standby.

3.Convert back to physical standby

startup mount force;
alter database convert to physical standby;
shutdown immediate;
startup mount;
alter database recover managed standby database disconnect from session ;
exit 

Note: Check the applicable syntax for your version. Oracle 19c USING CURRENT LOGFILE has been deprecated.

This is a far more streamlined approach compared to how it was done in Oracle 10g.

About the Author

Leave a comment

Send this to a friend