On Sun, Dec 4, 2011 at 7:14 PM, Alban Hertroys <haramrae@xxxxxxxxx> wrote: > On 4 Dec 2011, at 11:19, Phoenix Kiula wrote: .... > > INSERTs in the parent table don't need to check for any reference from the child table, since they're new; there can't be a reference. UPDATEs and DELETEs do though, whether you let them CASCADE or not. If you don't, then the database raises a foreign key constraint violation. If you do, then it needs to modify the relevant rows in the child table. > > Likewise, INSERTs and UPDATEs in the child table need to verify that - if their reference key changed - they're still referencing a valid row. Thanks Albert. Very useful. I had ON DELETE...ALSO DELETE rules earlier and in some cases they let some keys go by in associated tables. Hope foreign key constraint is more reliable! PK -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
