shrinking rbs?

Hey;

I'm trying to confirm/deny something our resident dba told me. A couple of days ago, I noticed that we were getting some ORA-1628 messages on our rollback segments indicating they'd reached their max_extents. I looked into it and sure enough they had - and optsize wasn't set.

I fixed the problem by manually shrinking all four rollback segments by:

alter rollback segment r0# shrink;

Our dba told me that I had risked getting a number of "snapshot too old" messages as some of those rollback segments could have been in use when I shrunk them. He told me the safer way to fix the issue is to alter the rollback segment offline then back online before shrinking.

Granted, I'm *way* on the junior side of junior when it comes to Oracle dba work; however, I have been doing a bunch of reading over the past several months. I don't remember reading anything anywhere about that. I would think that good error checking on Oracle's part, oxymoron that that is, would prevent the situation that our dba was postulating.

Is the dba correct? Should I have cycled the rollback segments before shrinking them? Fortunately, it's a moot point as there weren't any issues, but it'd be good to know for future reference.

Thanks for your time.

Doug O'Leary

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Douglas K. O'Leary
Senior System Administrator
dkoleary_at_mediaone.net