Re: Creating snapshots to avoid ORA-01555?

Thank you!

The worst thing about ORA-01555 is that for some reason it takes quite a few minutes for Oracle to "decide" that "snapshot too old". During this "a few" minutes the entire server becomes very slow. Is it a known effect of ORA-01555?

About creating snapshots. You are probably right! Using updatable snapshots will certainly even increase the rollback segs consumption, which would result in worse condition.

By the way, can it help if I forse all the small inserts to use one and the same rollback seg?

Misha.

In article <6jagb1$6ku$1_at_nnrp1.dejanews.com>,   cmohan_at_iname.com wrote:
>
> I don't know if there is anything better to handle this in Oracle 8, but in
> Oracle 7, ORA-01555 is a common error if rollback segments are not sized
> properly.
> Create a large rollback segment that can contain the changes made during the
> entire period a long query is running. Or, try to schedule the long running
> queris at a time when these small transactions are not intensive.
> In my opinion, creating snapshots to avoid ORA-01555 is an over kill!
>
> Good luck,
> CM
>
> In article <6j7jkf$9dq$1_at_nnrp1.dejanews.com>,
> larionov_at_yahoo.com wrote:
> >
> > Dear members of the NG,
> >
> > In the system I maintain there are a lot of small inserts
> > into a table and at the same time every hour there is running
> > "select" query on the same table. Of course, I am getting
> > a lot of ORA-01555 errors.
> >
> > I am thinking of using the updatable snapshots to avoid ORA-01555.
> > Somebody done this? Does it really help? Does it hurt the performance?
> >
> > Any help would be much appreciated!
> >
> > I am using Oracle 8.03 Server.
> >
> > Thank you.
> >
> > Misha.
> >
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-----== Posted via Deja News, The Leader in Internet Discussion ==----- http://www.dejanews.com/ Now offering spam-free web-based newsreading Received on Thu May 14 1998 - 10:55:22 CDT