If you are speaking about the conversion between physical and snapshot
standby: when the database is switched, a guaranteed flashback point is
created before being opened in read/write mode. The archive logs from the
primary database are still retrieved but not applied, so they are
effectively different databases each one doing different work.
Since the SCN changes for every commit, and sice the now diverging
databases will undergo commits in different number and time, they will have
different SCNs.
Once you revert the snapshot DB back to physical standby, it will be
flashed back to the flashback point created at first and the two databases
will be back being virtually aligned. I say virtually because there will
tipically be, even with no lag whatsoever, a couple number difference, so
they will realistically not be exactly the same in any case.
Regards,
Simone
2018-04-18 5:50 GMT+02:00 james Jose <josej8661@xxxxxxxxx>:
system change number on physical standby database and primary database are
same,correct?
The moment the physical standby is converted to an active test
database(read/write mode),The system change number we capture on the
standby database will still match with primary or will it be different?
Thanks
