RE: Checkpoint Question - need feedback

Madison (Particularly if the phys log is in its own dbspace) I see no problem with increasing the size given the size and cost of modern disks, and it is relatively easy to move and resize to physlog anyway so nothing special would be needed for in-place upgrades. As an aside, following a change to hardware/OS and upgrade from 7.31 to 9.4, I have reduced checkpoints from 13-20 seconds to < 1 second even with more buffers and a higher LRUMAX/MIN figures. Keith -> -----Original Message----- -> From: Madison Pruet [mailto:mpruet@comcast.net] -> Sent: Wednesday, July 05, 2006 11:22 PM -> To: informix-list@iiug.org -> Subject: Checkpoint Question - need feedback -> -> -> I've got a question for the user community. -> -> Checkpoints are a real pain because there is a period of -> time in which -> user threads are going to be blocked. -> -> I've been playing around with an idea in which I think I could do -> non-blocking checkpoints. The cost of doing this, however, would be -> that there would probably need to be a significant increase -> in the size -> of the physical log file. -> -> I know that implementing the fractional LRU min/max has -> helped reduce -> the impact of the checkpoint, but the fractional LRU min/max -> is not a -> guarantee - since it is possible that the LRU page writers -> won't be able -> to keep up with the current activity. -> -> Also - this idea would eliminate fuzzy checkpoints, which is -> probably a -> good thing since fuzzy checkpoints do impact the recovery -> time of the -> server. -> -> So - basic question --- Is the cost of the increased -> physical log file -> (maybe 3-4 times larger in some cases) totally outweigh the -> benefit of -> non-blocking checkpoints? -> _______________________________________________ -> Informix-list mailing list -> Informix-list@iiug.org -> http://www.iiug.org/mailman/listinfo/informix-list -> *********************************************************************************************** This message is sent in strict confidence for the addressee only. It may contain legally privileged information. The contents are not to be disclosed to anyone other than the addressee. Unauthorised recipients are requested to preserve this confidentiality and to advise the sender immediately of any error in transmission. This footnote also confirms that this email message has been swept for the presence of computer viruses, however we cannot guarantee that this message is free from such problems. ***********************************************************************************************