| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Michael Fuhr <mike(at)fuhr(dot)org> |
| Cc: | Bruno Wolff III <bruno(at)wolff(dot)to>, Martin Lesser <ml-pgsql(at)bettercom(dot)de>, Stephan Szabo <sszabo(at)megazone(dot)bigpanda(dot)com>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: Effects of cascading references in foreign keys |
| Date: | 2005-10-29 18:35:25 |
| Message-ID: | 12097.1130610925@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-performance |
I wrote:
> 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?
OK, I take back the possible-bug comment: the special case only applies
to the FK-side triggers, which is to say RI_FKey_check, and that routine
doesn't attempt to skip the check on equal old/new keys. I'm still
wondering though if the KeysEqual tests in the other RI triggers aren't
now a waste of cycles.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Thomas F. O'Connell | 2005-10-30 04:32:21 | Re: Effects of cascading references in foreign keys |
| Previous Message | Tom Lane | 2005-10-29 18:01:58 | Re: Effects of cascading references in foreign keys |