Re: Rollback Segment Trouble

Mark,

I agree that bad code is most often the cause of rollback problems.

However, programmers are not always free to insert commits into their processes. The business requirements might call for true transaction handling: all updates committed or all updates rolled back. Intermediate commits would prevent a total rollback. So, sometimes, you just have to make the rollback bigger!

Yes, there are other ways to handle this. If your business transaction must span multiple database transactions, you must provide application rollback code and application locking code on top of the database features.

Mark Gumbs wrote:

> I'm not a DBA or the greatest knowledge on rollback segments. However,
> experiences at my last job proved that everytime rollback segmentts were
> eaten up in this fashion, it was due to badly written or untuned code. If
> the code was updating lots of rows in a loop and not committing often, the
> error came up as well.
>
> Mark.
>
> Arthur Merar wrote in message <36e0d0b6.6002768_at_news.chaven.com>...
> >
> >Hello,
> >
> >I have a couple of questions revolving around rollback segments. Any
> >help would be appreciated.
> >
> >First, on Thursday I received a call that users were getting messages
> >of follback segments not being able to get any more extents. So, I
> >first extended all the rollback segments by 15 extents. That did not
> >help, so I extended the tablespace by 15, and that did not help
> >either. So, finally I shrunk all the rollback segments to optimal and
> >that worked.
> >
> >I used Desktop DBA to do some reverse engineering on the rollback
> >segment to see how it was built. Interesting.....although the Optimal
> >parameter was specified, there was no value. And, the Optimal column
> >in v$rollstat is NULL. Why is this?
> >
> >What is a good size for the optimal on a rollback segment? These are
> >short queries running against this database. Here is the code that
> >made all the rollback segments in my database:
> >
> >CREATE ROLLBACK SEGMENT RB01
> > TABLESPACE RBS
> > STORAGE (INITIAL 262144
> > NEXT 262144
> > MINEXTENTS 10
> > MAXEXTENTS 500
> > OPTIMAL )
> >
> >What should optimal be?
> >
> >Also, what should my normal response be when a rollback segment runs
> >out of room like that?
> >
> >Thanks for your help.
> >
> >Arthur
> >amerar_at_unsu.com
> >
> >
Received on Mon Mar 08 1999 - 16:48:45 CST