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.
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.