why would removing optimal setting help with snapshot too old? what I dont understand is that each of my DML transactions are independent of each other. They query and perform DML on different tables. None of them overlap. The only time they overlap is when they hit the data dictionary for some brief queries. > > From: Tim Gorman <[EMAIL PROTECTED]> > Date: 2003/06/05 Thu AM 03:25:36 EDT > To: Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]> > Subject: Re: Snapshot too old during stress test... how to avoid > > 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). > >
-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: <[EMAIL PROTECTED] 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).
