Added to TODO: * Improve referential integrity checks http://archives.postgresql.org/pgsql-performance/2005-10/msg00458.php --------------------------------------------------------------------------- Tom Lane wrote: > Michael Fuhr <mike@xxxxxxxx> writes: > > On Sat, Oct 29, 2005 at 09:49:47AM -0500, Bruno Wolff III wrote: > >> It looks like this feature was added last May, so I think it only applies > >> to 8.1. > > > Earlier versions appear to have at least some kind of optimization. > > Yeah. IIRC, for quite some time we've had tests inside the FK update > triggers to not bother to search the other table if the key value hasn't > changed. What we did in 8.1 was to push that test further upstream, so > that the trigger event isn't even queued if the key value hasn't > changed. (This is why you don't see the trigger shown as being called > even once.) > > Looking at this, I wonder if there isn't a bug or at least an > inefficiency in 8.1. The KeysEqual short circuit tests are still there > in ri_triggers.c; aren't they now redundant with the test in triggers.c? > And don't they need to account for the special case mentioned in the > comment in triggers.c, that the RI check must still be done if we are > looking at a row updated by the same transaction that created it? > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend -- Bruce Momjian <bruce@xxxxxxxxxx> http://momjian.us EnterpriseDB http://postgres.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
