Speaking of this trick with a txn in each RBS, I've got a shell script on my website (http://www.evdbt.com/tools.htm) that does just that. It is named "prevent1555.sh" which uses a stored procedure created by a SQL script named "prevent1555_ddl.sql"...
As Jared mentioned, it is kind of a last resort, but it works... on 6/4/03 4:05 PM, [EMAIL PROTECTED] at [EMAIL PROTECTED] wrote: > .. and if it still doesn't work, use the trick of putting a transaction > in > each of the rollback segments while the system is otherwise quiesced, > and *do not* commit or rollback the transactions. > > This forces the rollbacks to extend if necessary, they will never wrap > back to the first extent ( actually the second) as long as those > transactions > are not committed. > > It just uses a lot of disk space. Disk is cheap, right? :) > > Consider offlining all your production RBS and creating temporary ones > that you can easily drop later. > > I've used it with SAP client copies, which will not run to completion > without > doing this, at least on our system. > > Jared > > > > > > Kirtikumar Deshpande <[EMAIL PROTECTED]> > Sent by: [EMAIL PROTECTED] > 06/04/2003 09:45 AM > Please respond to ORACLE-L > > > To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> > cc: > Subject: Re: Snapshot too old during stress test... how to avoid > > > Try removing optimal setting, and shrinking RBS to the min extents (or > even below) before running > your tests. > > - Kirti > > > --- Garry Gillies <[EMAIL PROTECTED]> wrote: >> From memory (of a course attended looong ago), >> Oracle recommends one rollback segment for every >> three to four users. >> Four rollback segments between thirty six processes >> does seem a little mean. >> >> Garry >> >> >> >> >> >> <[EMAIL PROTECTED]> >> Sent by: [EMAIL PROTECTED] >> 04/06/03 13:59 >> Please respond to ORACLE-L >> >> >> To: Multiple recipients of list ORACLE-L > <[EMAIL PROTECTED]> >> cc: >> Subject: Snapshot too old during stress test... how to > avoid >> >> >> Im testing worst case scenarios right now. So Im doing batch >> updates,inserts,deletes and 'create table as' from a staging tablespace > of >> approximately 5GBs to a master tablespace of approximately 11GBs. >> >> Ive got my job queue processes set to 36 and Im running 36 at a time in >> the background in order to gather statistics and timing under worst case > >> scenarios. >> >> Im in 8.1.7.3 and I have increased the size of my RBS tablespace to 11GB > >> for this test. I have 4 standard RBS with optimal size set to 1GB. Why >> would I get a snapshot too old? I would think that 11GBs of rollback > would >> be big enough. Would increasing the number of Rollback segments avoid > this >> even though I have the same amount of space in the tablespace? >> >> In reality Im going to seriallize the process to avoid this and to > improve >> performance, however, I want to stress the system. >> >> any advice? >> >> -- >> Please see the official ORACLE-L FAQ: http://www.orafaq.net >> -- >> Author: <[EMAIL PROTECTED] >> INET: [EMAIL PROTECTED] >> > > > > __________________________________ > Do you Yahoo!? > Yahoo! Calendar - Free online calendar with sync to Outlook(TM). > http://calendar.yahoo.com -- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Tim Gorman INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).