Re: Remembering bug #6123

"Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov> writes:
> Going back through the patches we had to make to 9.0 to move to
> PostgreSQL triggers, I noticed that I let the issues raised as bug
> #6123 lie untouched during the 9.2 development cycle. In my view,
> the best suggestion for a solution was proposed by Florian here:

> http://archives.postgresql.org/pgsql-hackers/2011-08/msg00388.php

Do you mean this:

After every BEFORE trigger invocation, if the trigger returned
non-NULL, check if latest row version is still the same as when
the trigger started. If not, complain.

While that sounds relatively safe, if possibly performance-impacting,
it's not apparent to me how it fixes the problem you complained of.
The triggers you were using were modifying rows other than the one
being targeted by the triggering action, so a test like the above would
not notice that they'd done anything.

regards, tom lane