On Jun 3, 2011 10:04 AM, "Ian Hardingham" <i...@omroth.com> wrote: > > Thank you Igor, I'll do some more thorough profiling. > > When I run the query: > > UPDATE multiturnTable SET complete=1 WHERE id=-50000 > > This takes ~45ms (as reported by SQLite's profile) - is this in the > right ballpark? I'm running a fairly fast modern intel chip here.
In journal mode, yes: that's in the ballpark of what three fsync() calls should take, and that's how many fsync calls SQLite makes at commit time in journal mode. WAL mode should go faster because most often it does a single fsync(). But even three times faster will seem too slow to you, no doubt. To go faster consider batching updates into larger transactions (so as to amortize the synchronous I/O cost) or using fast flash devices to hold your DB. Also, serialize your writing if you can. Finally, consider some other method of obtaining durability, such as logging updates to a large, widely distributed memcache farm, then disable fsync for most transactions. Nico -- _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
