Re: Is it possible to get a ORA-01555: snapshot too old even if no tables were updated during select

In our last gripping episode Alexey Pashchenko <A.Pashchenko_at_vaz.ru> wrote:
> Check parameter log_checkpoint_interval - number of seconds between
 redo logs
> switching.
>
> Haild wrote:
>
> > we have a longrunning sql stemeten that select all rows from a
 large join that
> > meet a conditon, it runs for several hours due to amount of data
 being
> > processed.
> >
> > we are getting ORA-01555: snapshot too old eventhougth none of the
 source
> > tables were changed in any way no updates or inserts or deletes.
 in fact the
> > last timestamp on any of the talbes was over 13 hours earlier
> >
> > our logs show that the select was the only statement running at the
 time.
> >
> > everyone tells us that ORA-01555: snapshot too old is only done
 when a change
> > occurs to soruce tables if that ture can just a select being run.
> >
> > We have 10 rollback segements each 100M and total of 10 Gig in
 rollback
> > tablespace area.
>
>

Please see the following webpage:

http://home.clara.net/dwotton/dba/snapshot.htm

There is a fairly robust discussion of "snapshot too old" and the myriad causes.

--
David Fitzjarrell
Oracle Certified DBA


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