Thank you, Simon! Could you please say me what indexes will be correct? I'm trying CREATE INDEX mgwrInd1 ON mgWordsRelations (id_norm) CREATE INDEX mgwrInd2 ON mgWordsRelations (id_norminrel) CREATE INDEX wfInd1 ON wform (wordForm) CREATE INDEX wfInd2 ON wform (wordNorm) CREATE INDEX wfInd3 ON wform (ancode) but I have really high lack of perfomance. What is wrong with it? If you couldn't answer maybe you could post me some link to read about it? Thank you.
Simon Slavin-3 wrote: > > > On 15 Nov 2009, at 12:08am, Igor Tandetnik wrote: > >> select wf1.wordForm >> from wform wf1 join mgWordsRelations rel on (wf1.wordNorm = >> rel.id_norminrel) >> join wform wf2 on (rel.id_norm = wf2.wordNorm) >> where wf1.ancode = 'someAncode' and wf2.wordForm = 'someWord' >> order by random() limit 1; >> >> It's the same query, just written in a simpler form that might make it >> easier for SQLite to optimize. > > Also, we assume that you have all the best indexes to make the JOINs and > WHEREs work quickly. > > Simon. > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > -- View this message in context: http://old.nabble.com/Help-me-please-to-optimize-sql-query-tp26354687p26358412.html Sent from the SQLite mailing list archive at Nabble.com. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
