I'm currently dealing with a similar issue. I've found that the page_size PRAGMA setting can have a dramatic effect on how long it takes to "warm up" the table. On Windows 7, with page_size=1024, a SELECT COUNT(last_column) takes 40.2 seconds. page_size=4096 takes 15.5 seconds. page_size=8192 takes 8.5 seconds. This was done with a reboot between each test.
This page recommends a page_size of 4096: http://www.sqlite.org/cvstrac/wiki?p=PerformanceTuningWindows If I see better performance with the larger page sizes (going to test 16384 and beyond after this) is there any reason not to use them? Greg On Mon, Feb 21, 2011 at 4:37 PM, Stephen Oberholtzer < oliverkloz...@gmail.com> wrote: > On Mon, Feb 21, 2011 at 11:35 AM, Jim Wilcoxson <pri...@gmail.com> wrote: > > On Mon, Feb 21, 2011 at 11:05 AM, Sven L <larvpo...@hotmail.se> wrote: > >> > >> Thank you for your detailed explanation! > >> First, can you please tell me how to purge the cache in Windows 7? This > could be very useful for my tests! > > > > Sorry, dunno for Windows. On Mac OSX it is the purge command, in the > > development tools. On Linux, you do: echo 3 > > > /prog/sys/vm/drop_caches > > Just make sure you either (a) quote the 3 (echo '3' > > /proc/sys/vm/drop_caches) or (b) put a space between the 3 and the >. > If you don't quote it, and you don't put the space in (echo > 3>/proc/sys/vm/drop_caches) it doesn't do anything, for reasons I > won't go into. > > -- > -- Stevie-O > Real programmers use COPY CON PROGRAM.EXE > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
