Re: foreign key locks

Jaime Casanova <jaime@2ndquadrant.com> writes:
> On Thu, Jun 14, 2012 at 11:41 AM, Alvaro Herrera
> <alvherre@alvh.no-ip.org> wrote:
>> This is v12 of the foreign key locks patch.

> Just noticed that this patch needs a rebase because of the refactoring
> Tom did in ri_triggers.c

Hold on a bit before you work on that code --- I've got one more bit of
hacking I want to try before walking away from it.  I did some oprofile
work on Dean's example from
<CAEZATCWm8M00RA814o4DC2cD_aj44gQLb0tDdxMHA312qg7HCQ@mail.gmail.com>
and noticed that it looks like ri_FetchConstraintInfo is eating a
noticeable fraction of the runtime, which is happening because it is
called to deconstruct the relevant pg_constraint row for each tuple
we consider firing the trigger for (and then again, if we do fire the
trigger).  I'm thinking it'd be worth maintaining a backend-local cache
for the deconstructed data, and am going to go try that.
        regards, tom lane