Re: Autoextend for rollback

Don't know whether this counts as thoughts, dark corners, nooks and crannies or conventional wisdom, but I've always advocated not using auto extend, particularly for rollback segment tablespaces and temporary tablespaces. The reasoning is pretty obvious. Rogue processes can really blow things away if you do use it. At least without autoextend they only fill the tablespace.

HTH. Pete

Kenneth C Stahl wrote:

> Has anyone ever used auto extend for tablespaces that only contain
> rollback segments?
>
> For example, let's say I create a tablespace called RBS which will only
> hold rollback segments and give it a size of 15M. I then create ten
> rollback segments with INITIAL 100K NEXT 100K OPTIMAL 200K MINEXTENTS 2
> MAXEXTENTS 249. Quite obviously, the first time that I have a
> transaction which causes a rollback segment to grow towards 249 extents
> I'll get the "snapshot too old" error message and my transaction will
> rollback. However, if I give the tablespace the ability to auto extend
> then the tablespace will grow as needed. I realize the risk here is that
> if I have multiple transactions that are all causing the rollback
> segments to grow to many extents that I'll end up with a collossal
> tablespace but that is something I could always monitor and adjust as
> needed - but at least I wouldn't be beeped in the middle of the night
> when batch processing is going on and some job aborts because I ran out
> of space in the RBS tablespace.
>
> Thoughts? Dark corners? Nooks and crannies? Convential wisdom?
>
> Ken

--

Regards

Pete

Received on Fri Jun 18 1999 - 11:55:37 CDT