RE: Initiating Checkpoints manually

I imagine you would gain some advantage by going up to 128 LRU's. (and upping cleaners as well) But then again, I imagine lots of things Will >===== Original Message From "Vinod Bhansali" <iiug@hotmail.com> ===== >I have >LRU_MAX_DIRTY 3 >LRU_MIN_DIRTY 1 >BUFFERS 300,000 (system page size 2k) >LRUS 64> > >Thanks >Vinod Bhansali >Informix DBA >DSL Transportation > > > > > >>From: "Rudolf Fernandes" <rferdy@nortelnetworks.com> >>To: Vinod Bhansali <iiug@hotmail.com> >>Subject: Re: Initiating Checkpoints manually >>Date: Thu, 01 Jun 2000 15:34:14 -0400 >> >>Vinod Bhansali wrote: >> >> > Hello friends, >> > >> > I want to tune the checkpoint duration by trying different values for >>the >> > ckptintvl. >> >>CKPTINTVL is not normally used to tune one's checkpoint duration, although >>in >>theory, like the physical log size, it can be used. Rather, in the tuning >>perspective, it provides a means of balancing disk writes against duration >>of >>Fast Recovery. >> >>One's checkpoint duration, keeping OS/Hardware/Db space layout variables >>constant, is primarily dependant on the number of dirty buffers at >>checkpoint >>time - those have to be flushed to disk and it is this process which takes >>time. The number of dirty buffers, in turn, is primarily dependant on 3 >>onconfig parameters - LRU_MAX_DIRTY, LRU_MIN_DIRTY and BUFFERS. >> >>You should be fiddling with LRU_MAX_DIRTY & LRU_MIN_DIRTY to tune your >>checkpoint duration. Unfortunately, that does require you to bounce your >>engine. >> >>Rudy >> >> >> > But as we need to initialise shared memory after each change I am >> > planning to initiate checkpoints manually by writing some shell as below >> > >> > onmode -c>> > sleep 50 >> > >> > What do you say? Is it ok? Has anyone faced any problems in this? >> > >> > Thanks in advance >> > Vinod Bhansali >> > Informix DBA >> > DSL Transportation >> > ________________________________________________________________________ >> > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com >> > >________________________________________________________________________ >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/ ------------------------------------------------------------