John Fabiani <jo...@jfcomputer.com> wrote: > Hi, > I have read a few articles and I'm not sure if it's me or the authors but I > do > not believe my question was answered. > > If I have table that has a PK and a FK - will the planner use the FK just > same > as it would use the PK? IOW's is a FK also an index used by the planner? > > I have a lagacy table that contains a FK constraint (vendor_id --> > vendor_info). I believe I need an index to improve the performance of a > query > because I'm using the column as part of my join. Explain does not appear to > use it as an index (instead of a seq scan it uses a hash join). But the > table > all ready has a FK key contraint on the column.
Yes, for large tables you have to create a own index on your fk-column. Andreas -- Really, I'm not out to destroy Microsoft. That will just be a completely unintentional side effect. (Linus Torvalds) "If I was god, I would recompile penguin with --enable-fly." (unknown) Kaufbach, Saxony, Germany, Europe. N 51.05082°, E 13.56889° -- Sent via pgsql-sql mailing list (pgsql-sql@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-sql
