Re: Bring Online down in middle of t

>--------------------------( Forwarded letter 1 follows )--------------------- >Date: Monday, 3 November 1997 10:06pm >From: "* N O - S P A M 26894 cosmo"@echonyc.com >Subject: Bring Online down in middle of transaction rollback? >Date: Mon, 3 Nov 1997 23:55:51 -0600 >Reply-To: Cosmo Lee <"* N O - S P A M 26894 cosmo"@echonyc.com> >Organization: Multi-User Computer Systems >Sender: informix-list-owner@rmy.emory.edu >To: informix-list@rmy.emory.edu >X-Informix-List-Id: <news.44848> > >What is the effect of bringing Online down in the middle of a >transaction being rolled back? Is it meant to recover gracefully from >this kind of thing? If so, in reality, does it actually do so (recover >gracefully, that is)? > >I've got a client who pulled a bone-headed move of running two huge >deletes at the same time. After eight hours, the 800,000 row locks have >been exhausted, and all users are locked out of the database. So, we're >going to have to wait another eight hours, at least, for the >transactions to roll back. > >I'm wondering if there are any ways to speed this process. One thought Sorry, I've been thinking some more... If you reboot Online then OFF_RECVRY_THREADS will be used during the logical recovery when online restarts. (Online Admin Guide Volume 2 Page 38-46). Question: Can >1 thread be used to rollback a single transaction? Question: How does decided how many threads to use when rolling back a transaction? The description for ON_RECVRY_THREADS does NOT indicate that this number of threads is used to rollback a transaction, however it does say that "The maximum degree of parallel processing occurs when the number of recovery threads matches the number of tables being recovered." >that came to mind was to bring Online down, add more locks, then bring >it back up. My concern is whether Online is meant to recover gracefully >from being shut down in a middle of a transaction rolling back. 800,000 >rows is a lot to modify, so I'm a bit queasy about interrupting that >kind of transaction. Anybody w/ experience like this? > >Is there some other way that I could speed this process to get users >access to the DB more quickly? > >As far as I can tell, there is not way to add more locks while Online is >running. Please tell me if I'm incorrect. > >TIA. > >-- >* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * >ADDRESS ALTERED TO FOIL SPAMMERS: Remove "*NO-SPAM*" to reply. > >Cosmo Lee Multi-User Computer Systems Brooklyn, NY > > "JUST SAY 'NO' TO SPAM" >* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > > -- David Williams