Re: Rollback Segs

that all depends on what you mean by 'having a rollback segment of 30M'. When you create your rollback segments you don't explicitly specify a 'size', but you specify initial and next extent sizes and minimum extents. Now, if you are saying that your (initial * minimum) equals 30 MB, then having an optimal of 29 MB won't do you any good at all. As transactions use additional extents in the rollback segment, it grows beyond your (initial * minimum). Without the use of the optimal clause, if you had a rollback segment that extended to 100 MB to allow long-running transactions to complete, it will not relinquish those extra extents when the transaction finishes, and at some point you will most likely encounter an 'unable to allocate extent' error message when one of the other rollback segments tries to extend.

on the other hand, if you actually mean that the size of your rollback tablespace is 30 MB, and your rollback segments are something smaller than that, then an optimal of 29 MB may be of benefit.

HTH,
Roy

In article <7o73ke$m2p$1_at_nnrp1.deja.com>,   bandiren_at_my-deja.com wrote:
> I want to know what are the advantages and disadvantages of having a
> rollback segment of
> 30M and with optimal size 29M.
>
> Thanks
> Nilima
>
> Sent via Deja.com http://www.deja.com/
> Share what you know. Learn what you don't.
>

Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't. Received on Tue Aug 03 1999 - 14:41:13 CDT