Re: Explanation on recovery rollback phase.

From: Johnny Chan <j4ychan_at_PROBLEM_WITH_INEWS_GATEWAY_FILE>
Date: 1997/04/11
Message-ID: <5ilrsp$dk1@gw.PacBell.COM>#1/1

Guilherme Mesquita Chaves (chavesgm_at_br.homeshopping.com.br) wrote:
> I'd like to know when does the oracle execute the rollback at recovery
> using the rollback segs and the rollback stored at the redo log. What's
> the criteria? Suposse i lost the rollback segs in a media failure. What
> wold be my source for doing a rollback at the recovery?

during recovey, Oracle performs a rollback completely after the rollforward. so in your particular example, when you are recovering the rollback seg tablespace, Oracle would roll forward all the redo to reconstruct the rb segs. Once the roll forward is complete (or if you intentionally stop recovery to perform point-in-time) and open the db, Oracle will read the newly reconstructed rb segs and rollback any uncommitted transcations.

Johnny Chan
Independent Oracle Specialist Received on Fri Apr 11 1997 - 00:00:00 CDT