>>>>> "Tomas" == Tomas Berndtsson <[EMAIL PROTECTED]> writes: Tomas> Laurent Martelli <[EMAIL PROTECTED]> writes: >> I have this query : >> >> select distinct on (Pictures.PictureID) * from Pictures where >> Pictures.PictureID not in (select distinct PictureID from >> Keywords); >> >> and I find it a bit slow. Does anybody have suggestions to run >> this faster ? (I have indexes on PictureID on both Pictures and >> Keywords) Tomas> Try this instead: Tomas> select distinct on (Pictures.PictureID) * from Pictures where Tomas> not exists (select distinct PictureID from Keywords where Tomas> Pictures.PictureID=Keywords.PictureID); Tomas> I've found that it's usually faster, probably because it can Tomas> use indices better. It is indeed much faster. Thanks to all of you who answered so fast. -- Laurent Martelli [EMAIL PROTECTED] http://www.bearteam.org/~laurent/ ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
