Jeff Janes <jeff.janes@xxxxxxxxx> writes: > Will PG allow you to add a FK constraint where there is no usable > index on the referenced side? It will not, because the referenced side must have a unique constraint, ie an index. The standard performance gotcha here is not having an index on the referencing side. But that only hurts when doing UPDATEs/DELETEs of referenced-side keys, which as far as I gathered was not the OP's scenario. regards, tom lane -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
