Re: Problem with Rollback segment

The snapshot too old error is occuring as the long running query cannot retrieve a read -consistent view of the data because of the simulatneous updates and inserts that are running on the database that are actually modifying the data that the long running query is modifying. You have two options:
1) Do do run the log running txn along with the OLTP 2)Or allocate a big rollback segment and see to it that you set transaction on the inserts and update statements so that all these changes will go into the dedicated large rollback segment , so that later on the long running query has a higher probability of retrieving data from the rolllback segement.

Cheers
Sanjay T Mathew
Oracle DBA

Dan Norris wrote:

> using "set transaction" for a query has no effect (that I know of).
> select's are not transactions. If you are doing updates, inserts, or
> deletes that are part of a large transaction, then your "set transaction"
> statement will have impact.
>
> Dan
>
> dtang_at_minn.net writes:
>
> >Hi:
 

> >I got a very serious problem. I have a huge query to update a large
> >table. It runs several hours, then dead with oraerr 01555. Snapshot
> >too old, the rollback segment R05 is too samll.
> >Then I creat a large rollbak segment O08, then
> > use set Transaction use rollback segment r08, and run that query
> >again.
> >After hours , it died again with same error 01555, but it still say:
Received on Thu Mar 26 1998 - 00:00:00 CST