On 26 Jul 2011, at 9:30am, Григорий Григоренко wrote: > I need query to be ORDER BY id DESC. I've dropped this ORDER BY to simplify > my case. But in real-life app I need it. > > So, index on (kind, computer) has these index records: > > [ KIND ] [ COMPUTER ] [ ID ]
I don't know that SQLite does an inherent addition of the 'id' column to all INDEXes. Some index implementations do this because their algorithm requires that all positions in an index are unique, but I don't think SQLite works like that. I think that if you want 'id' to be part of an index you have to say that in the definition. Nevertheless this still doesn't explain why your first run of a query is so much slower than subsequent runs. SQLite's cache size is set here: http://www.sqlite.org/pragma.html#pragma_cache_size If the cache size described there doesn't explain the behaviour you're seeing, the problem isn't with SQLite, it's in your application or the OS or your hardware. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
