Re: Is using OPTIMAL in RBS ORA-1555 prone?

I think the short answer is Yes.

Most good DBAs would not recommend use of OPTIMAL; rather create an appropriate number of rollback segments of appropriate size to support your application, so that any long running transaction has a better chance of finding the 'before image' it needs.

In the real world though, I doubt if you can ever make it 100%; even with 9i flashback queries.

Just my 2p; additions and corrections welcomed...

Paul

"Syltrem" <syltrem_at_videotron.spammenot.ca> wrote in message news:lbac8.5603$EI.30616_at_tor-nn1.netcom.ca...
> If using OPTIMAL setting in the rollback segments, am I more likely to
have
> ORA-1555 snapshot too old?
>
> That is, Oracle will shrink the rollback segment at the start af any new
> transaction, so it may thus drop information required by that other
> long-running process.
>
> Even so, you can never tell when a rbs extent will be reused so how can
you
> make 100% sure you will not get this error? Users get it every couple of
> weeks and I can't do an alter session use rollback segment xxxx in this
> application.
>
> Any suggestions appreciated.
>
> --
>
> Syltrem
> http://pages.infinit.net/syltrem (OpenVMS related web site - en français)
> To reply to myself directly, remove .spammenot from my address
>
>
>
Received on Mon Feb 18 2002 - 14:18:23 CST