On Tue, 19 Dec 2006 13:52:19 -0500, you wrote: >I've started to use SQLite and it works fine - except for performance. The >application gets requests (possibly from many users) and does a few >transactions on the database. (eg. create a context for the request; later >it may be updated and when the user releases the record is deleted.) > >I tried all three sync methods and with FULL, NORMAL and OFF. For 100 >transactions (request / check / release) I see 800 open/close (in 1200msec), >5800 lock/unlock (22 msec) and 600 (FULL - 17,000 msec), 400 (NORMAL - >12,000 msec) or 0 (OFF) file flush operations. The latter is really slow but >I understand it. (Have to wait for the actual disk operation to complete). > >For this particular application it would NOT be a problem to lose like 2-5 >seconds of transactions. I wonder if it is possible to tell SQLite to "hold >off" the transactions, ACCUMMULATE them until a certain time (or if cache >memory is exhausted - which is not yet the case as we have a modest >database), then make a BIG COMMIT (ie. all previous transactions committed >or none). That way it's still transactional (ie. no currupted database - I >really don't want to use sync = OFF) but the I/O performance wouldnt slow >down serving requests. > >Anybody has done that already? If yes, where can I find such modified SQLite >source? >I saw that all file I/O related calls are in two files: pager.c and >vdbeaux.c so they are already well isolated and relatively easy to >understand. > >Any help for such "delayed" transaction method in SQLite? >(I tried to find any relevant message in the email archives but came up >empty.) > >Thanks, > >Laszlo Elteto >CISSP, System Architect >SafeNet, Inc.
I wonder if shared cache would help you? http://www.sqlite.org/sharedcache.html In general, in a high concurrency environment sqlite might not be a suitable solution. http://www.sqlite.org/whentouse.html -- ( Kees Nuyt ) c[_] ----------------------------------------------------------------------------- To unsubscribe, send email to [EMAIL PROTECTED] -----------------------------------------------------------------------------
