Re: Making AFTER triggers act properly in PL functions

Stephan Szabo <sszabo@megazone.bigpanda.com> writes:
> On Wed, 8 Sep 2004, Tom Lane wrote:
>> I think the main concern here would be the space cost of
>> adding still another field to the trigger records ... is it worth it?

> Would it be possible to basically alias the space for dte_done_xid to hold
> either the xid if it's done or the <whatever> if it's in progress? That's
> ugly, but it would presumably not increase the size of the record.

Yeah, I was wondering the same, but hadn't quite worked out the details.
The difficulty is that if trigger execution is abandoned due to an
error, you'd have to be able to recognize which entries weren't really
"in progress" anymore.  If the values aren't XIDs, I'm not sure how to
do that.

One thing I was looking at was that we aren't using nearly all the bits
of dti_state.  It'd be possible to narrow that to int16 and then
shoehorn a 16-bit query nesting depth counter into the freed space.
Not sure if this is enough though.

Actually, I'd really like to get it back down to the 7.4 size, which was
already too big :-(.  That might be a vain hope though.
        regards, tom lane