Thanks for sending in the performance regression report. On Wed, Oct 22, 2014 at 1:51 PM, Tomislav Ljubej <spor...@gmail.com> wrote:
> Hello, > > There is a performance regression in the media player Banshee on the > query that is in the attachment. The query takes about 13 seconds on > my i7 4770 processor. I tried the latest stable version before the > current one which is 3.8.6.1 and the performance regression doesn't > happen, the query completes in less than half a second. > > The query is run 3 times at Banshee startup so it slows down the > startup of the application significantly. > > Also attached is the .schema output for the database Banshee uses. I'm > not sure why the 'CoreCache' table isn't mentioned in the schema but > I'm pretty sure it's actually referring to 'CoreCacheModels', I got > the query from Banshee's debug output so it may not reflect the actual > names in the database. > Several problems: (1) Your "query" is actually two statements: a DELETE followed by an INSERT. The INSERT is fed from a SELECT. Would I be correct in assuming that the SELECT is the problem? (2) You are right that CoreCache is not in the schema, so the SELECT is not valid. I tried changing the name of the CoreCache table in the SELECT into CoreCacheModels, but then it complains that CoreCacheModels has no ItemID column. (3) After you determine the correct schema and query, it would be helpful to us if you can send us the output of ".fullschema". The ".fullschema" output includes the sqlite_stat1 and sqlite_stat4 tables (if they exist) which contain histogram data used by the query planner. Those table (if they exist) are needed by us in order to reproduce the behavior your are observing. (4) If you are able to send us your complete database file, perhaps by private email, that would be even more helpful, but is not absolutely necessary. > > -- > Tomislav Ljubej > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > -- D. Richard Hipp d...@sqlite.org _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
