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