On Mon, 2003-11-17 at 17:14, Peter Eisentraut wrote: > Michele Bendazzoli writes: > > > ALTER TABLE public.table1 > > ADD CONSTRAINT table1_pkey PRIMARY KEY(a, b, c); > > > > are the indexes over (a) and (a, b) redundant (and so useless)? > > Exactly.
> > p.s. I know, I'll have to begin to use the explain command ... > > I promise I'll do it ;-) > > You could also have read the documentation about multicolumn indexes, > because it contains exactly this example. Thank you. I have read the chapter but I wonder if the implicit index created by the primary key behaves as a normal indexes at all. ciao, Michele ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html