On Tue, 28 Aug 2007 13:19:32 -0400 Tom Lane <tgl@xxxxxxxxxxxxx> wrote: > Josh Trutwin <josh@xxxxxxxxxxxxxxxxxxx> writes: > > I am curious if there are any rules of thumb for when to index a > > foreign key column? > > (You realize of course that there's already an index on the > referenced column, else you wouldn't have been allowed to reference > it.) Certainly - If there were no index on the referenced PK / UNIQUE col I'd be concerned. > You need an index on the referencing column unless the referenced > table is pretty static: DELETEs in the referenced table will be > real slow without it, and also UPDATEs that change the referenced > column. However there are applications where this never happens, > or so infrequently that it's not worth paying to maintain an extra > index on the referencing table. I would say my app falls into this category. Thanks for your help, Josh ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
