On Mon, 2003-11-17 at 18:13, Tomasz Myrta wrote: > Dnia 2003-11-17 19:00, Użytkownik Michele Bendazzoli napisał: > > a is always present in the queries ... and other that (a, ab, abc) i > > have only to query (ac): so I think I have to index separately only > > (ac). > > For such cases consider changing primary key from (a,b,c) into (a,c,b)
b,c are exactly simmetric, so if I change the primary key to (a,c,b) I have to index separately (a,b) ... rigth? ciao, Michele ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly