I solved my "inner/outer" problems by compiling Sqlite with SQLITE_ENABLE_STAT2=1.
That flag makes it better at choosing the inner table! > To: sqlite-users@sqlite.org > From: itandet...@mvps.org > Date: Wed, 11 Nov 2009 12:03:06 -0500 > Subject: Re: [sqlite] optimization question > > Tim Romano <tim.rom...@yahoo.com> wrote: > > I've read http://www.sqlite.org/optoverview.html but don't find my > > answer there. > > > > In the following query, WOIDS has 4 million rows and CORNFIX has > > 25,000 rows. > > > > UPDATE WOIDS > > SET corn = 1 > > WHERE EXISTS > > ( > > SELECT * > > FROM CORNFIX > > WHERE (cornfix.col_1 = woids.ttl) AND (cornfix.col_2 = > > woids.pos) AND (cornfix.col_3 = woids.wrdid) > > ) > > Try this instead: > > update WOIDS set corn=1 where rowid in > (select w2.rowid > from cornfix join woids w2 on ( > cornfix.col_1 = w2.ttl AND cornfix.col_2 = w2.pos AND cornfix.col_3 = > w2.wrdid) > ); > > I'm not sure, but this structure might help SQLite choose cornfix for the > outer loop. > > Igor Tandetnik > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _________________________________________________________________ Hitta hetaste singlarna på MSN Dejting! http://dejting.se.msn.com/channel/index.aspx?trackingid=1002952 _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
