thanks for answers Luigi.
2014-10-25 15:46 GMT+02:00 Richard Hipp <d...@sqlite.org>: > On Thu, Oct 23, 2014 at 11:55 AM, Luigi Iemma <iemmalu...@gmail.com> > wrote: > > > Hi, > > > > SELECT TdoIdoc,RdoCart,RdoQuat > > FROM Tesdoc > > INNER JOIN Rigdoc ON RdoIdoc BETWEEN TdoIdoc*10000000 AND > > TdoIdoc*10000000+9999999 > > WHERE TdoTipo=60 AND TdoAnno BETWEEN 2014 AND 2014 > > GROUP BY TdoIdoc > > > > When I run this query on 3.8.5 it takes 0.126 seconds, > > when I run this query on 3.8.7 it takes 17.37 seconds > > > > Version 3.8.7 (also version 3.8.6) is using a different query plan. > > Actually, 3.8.6 and 3.8.7 are making the better choice, based on the > information at hand. The query planner just doesn't have sufficient > information to make a good choice in this case. As Simon pointed out, you > can run ANALYZE to give the query planner more information. Or you can > give it hints. One possible hint is to add a "likelihood() function around > the TdoTipo=60 constraint: > > SELECT TdoIdoc,RdoCart,RdoQuat > FROM Tesdoc, Rigdoc > WHERE RdoIdoc BETWEEN TdoIdoc*10000000 AND TdoIdoc*10000000+9999999 > AND likelihood(TdoTipo=60, 0.01) ----<<< HERE > AND TdoAnno BETWEEN 2014 AND 2014 > GROUP BY TdoIdoc; > > > > -- > D. Richard Hipp > d...@sqlite.org > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
