Is using OPTIMAL in RBS ORA-1555 prone?

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