Re: Rollback segment too large

Brian

The lack of an OPTIMAL setting is what we had in version 6 days, and one of the things we used to have to do as a result was manually drop and recreate the rollback segments, because eventually they ran out of extents. It's not just the size of the transaction, but also the number of active concurrent transactions you need to be careful of.

It just doesn't make sense to me that we introduce a new feature to remove one of the manual interventions we needed to do in version 6, and then not to use it for a perceived performance problem that is probably more due to an incorrect OPTIMAL setting than the nature of the OPTIMAL setting.

HTH. Pete

Brian Peasland wrote:

> > shrink back (i.e. it's trying to shrink to OPTIMAL too often). Also,
> > leaving the rollback segment without OPTIMAL set ensures you will
> > eventually hit MAXEXTENTS and users would receive an error that they
> > shouldn't.
>
> How does not having an OPTIMAL setting ensure that you will reach
> MAXEXTENTS? After the transactions are committed and the information
> removed from the rollback segment, it just won't shrink. But the segment
> will still have room in it for future transactions. If the rollback
> segment reaches MAXEXTENT, then it seems to me that the transaction(s)
> need bigger rollback segments just to complete.
>
> Any comments?
>
> Brian

Received on Fri Aug 27 1999 - 13:01:20 CDT