On Wed, 8 Sep 2004, Tom Lane wrote:
> Hmm. Here's a slightly off the wall idea: following SET CONSTRAINTS,
> scan the pending-triggers list twice. The first time, you determine
> which triggers you need to fire, and mark them "in progress" by your
> transaction. The second time through, you actually fire the ones you
> marked, and change their marking to "done". The "in progress" ones
> wouldn't be touched by the hypothetical inner SET CONSTRAINTS.
>
> It wouldn't quite work to use just transaction ID as the marker, since
> the inner SET CONSTRAINTS is very possibly done without using a
> subtransaction. But command ID or query nesting level or some such
> would work. 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.