RE: Logical logs

I also feel that I should keep LTXHWM & LTXEHWM 50 & 60. And increase the no. of logs and also start tunning the application to make transactions small. Thanks for your advice Vinod Bhansali. >From: William Rice <ricew@operamail.com> >To: Girish Punjabi <girishpunjabi@my-deja.com>, informix-list ><informix-list@iiug.org> >Subject: RE: Logical logs >Date: Wed, 24 May 2000 08:01:30 -0400 > >I hope you have LBU_PRESERVE set to 1. > >I personally have no qualms with having more than enough space dedicated >to logical logs. The amount of money spent on extra disk space is easily >saved by not having a database locked exclusively to rollback long >transactions, >especially if you run out of log space. > >I personally would never change the long transaction high water marks. I >don't >like getting woken up in the middle of the night and being told the >database >is hung... > >Will > >===== Original Message From Girish Punjabi <girishpunjabi@my-deja.com> >===== > >HI Vinodh, > > > >Nothing wrong with more logical logs except that is is inefficient from > >an administrative point of view. > >Instead of having 120 logical logs of 2MB each you can have 30 logs of > >8MB each.You can also set LTXHWM & LTXEHWM are 80 and 90 > >respectively.We have overcome the long transaction problem here by > >deviating from Informix suggested values of 50 and 60. > >Also , as William suggested, you need to have a look at the code as > >well , as no amount of tuning can help if the code is inefficient. > > > > > >In article <8ge25v$s64$1@news.xmission.com>, > > William Rice <ricew@operamail.com> wrote: > >> > >> I do not feel their is anything wrong with having that many logical > >logs. > >> One thing you might want to establish is why you are having long > >transactions > >> and whether or not what is being done is required to be one > >transaction. > >> > >> If the cause is a process which is required to be updated in one > >transaction > >> you have no choice but to increase the number of logs. > >> > >> If the cause of the long transactions is a purge or something of that > >nature, > >> which can be done in smaller increments without effecting the > >validity of the > >> data, you might want to look into making the purge use a select cursor > >> and deleting each record and committing periodically.(If their is a > >better way > >> to do this I would love to hear it.) If you just increase the number > >of logs, > >> as > >> the amount of data purged grows, the likelihood of hitting a long > >transaction > >> again grows. A program which commits at regular intervals bypasses > >> these emergencies. > >> > >> If the cause of the long transactions is a lock held for an > >inordinate period > >> of time, it might be worth implementing some sort of timing mechanism > >> to cause the user to abort after holding a lock for some period of > >time, > >> or rewriting the application to not hold locks while waiting for user > >input. > >> > >> Hope this helps, > >> Will > >> >===== Original Message From "Vinod Bhansali" <iiug@hotmail.com> ===== > >> >In our system, I am noticing Long Transactions being caused > >sometimes. We > >> >have 80 log files, each of size 2048. LTXHWM & LTXEHWM are 50 & 60. > >I don't > >> >want to increase them. I am planning to increase the no. of log > >files to 120 > >> >or to 160. Are there any pros and cons of having more no. of logical > >log > >> >files. We have continuous logical log backup running and we take > >zero level > >> >db backup daily using ontape. > >> > > >> >Thanks in advance > >> >Vinod Bhansali > >> > >>_______________________________________________________________________ > >_ > >> >Get Your Private, Free E-mail from MSN Hotmail at > >http://www.hotmail.com > >> > >> ------------------------------------------------------------ > >> This e-mail has been sent to you courtesy of OperaMail, as a free > >service from > >> Opera Software, makers of the award-winning Web Browser, Opera. > >Visit us at > >> http://www.opera.com/ or our portal at: http://www.myopera.com/ Your > >free e-mail > >> account is waiting at: http://www.operamail.com/ > >> ------------------------------------------------------------ > >> > >> > > > > > >Sent via Deja.com http://www.deja.com/ > >Before you buy. > >------------------------------------------------------------ >This e-mail has been sent to you courtesy of OperaMail, as a free >service from >Opera Software, makers of the award-winning Web Browser, Opera. Visit us >at >http://www.opera.com/ or our portal at: http://www.myopera.com/ Your free >e-mail >account is waiting at: http://www.operamail.com/ >------------------------------------------------------------ > ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com