On 4 December 2013 01:24, Robert Haas <robertmh...@gmail.com> wrote: > Yeah, more or less, but the key is ensuring that it wouldn't let you > create the constraint in the first place if the partial index > specified *didn't* match the WHERE clause. For example, suppose the > partial index says WHERE parent_entity = 'event' but the constraint > definition is WHERE parent_event = 'somethingelse'. That ought to > fail, just as creating a regular foreign constraint will fail if > there's no matching unique index.
The where clause only applies to queries against the FK table, and we don’t currently fail if there isn’t a matching index on the fk column when creating a FK (I’ve been bitten by that before). We fail if there isn’t a unique index on the referenced table/column(s), but queries against that table on insert/update not the FK table are unchanged (save that we don’t bother with them at all if the where clause expression fails for the given tuple). Cheers Tom -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
