Rollback segments not shrinking back to OPTIMAL size!
Date: 1996/08/12
Message-ID: <320F53F7.D24_at_cincom.com>#1/1
All,
We have observed that with some of our application's long-running batch
jobs, the rollback segments do not always shrink back to their OPTIMAL
size. The way I understand rollback segments is that you are not
guaranteed that a particular transaction will use a particular rollback
segment. So, a transaction may cause a rollback segment to grow rather
large, then commit, and the next transaction may not use the same
rollback segment. Especially if the batch job is the only thing running
in the database.
We are using Oracle 7.1.6.2 on HP-UX 10.01. We have one rollback
segment tablespace with 4 rollback segments, INITIAL and NEXT extents
5MB and OPTIMAL 20MB. When the batch job runs, one rollback segment
grows very large (~50MB) before the job does the first commit. Then it
resumes processing, and appears to use another rollback segment, which
grows to ~170MB, and commits again. Eventually one of the rollback
segments gives an ORA-01650 error because it runs out of room in the RBS
tablespace. However, the other rollback segments are still at their
expanded sizes of 50MB and 170MB.
QUESTIONS
Thanks,
Brian
--
Brian M. Biggs mailto:bbiggs_at_cincom.com
Cincom Systems, Inc. voice: (513) 677-7661
http://www.cincom.com/
Received on Mon Aug 12 1996 - 00:00:00 CEST