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Oracle Crash Recovery and SCN

I have 2 Oracle servers in a failover solution. I also have a PL / SQL procedure that uses SCN numbers.

If, during this procedure, one server fails and processing switches to the second server, does that mean that the SCN will be the same on the second server?

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If your fault tolerance solution is Oracle RAC and you are technically using multiple oracle instances with the same database, then:
Since SCN (System Change Number) is a database concept and not an oracle instance concept then during this procedure when one server fails and processing switches to the second server, SCN will be the same
BUT
as fact

There are ALWAYS transactions in the database, ALWAYS. SMON and many other background processes always do the work, the database (unless it is read-only) always making a deal.



therefore SCN always changes to internal actions of oracles,

you cannot relay over SCN, so as not to change during the swiching process

take a look at this: SCN by Tom Kyte

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