Re: Sketch of extending error handling for subtransactions in functions

Tom Lane wrote:
> One issue is that it may break existing PLs that override Warn_restart,
> since the semantics of doing that will have changed a bit. We can
> easily fix the PLs that are in our own CVS, but what are the
> implications for other PLs such as PL/R and PL/SH? Joe, Peter, any
> comments?

> I am somewhat tempted to rename the setjmp variable Warn_restart to
> something else, so as to catch any code that is still expecting the
> old behavior (besides, it was never a very good name anyway). On the
> other hand, there may be cases where a PL's code doesn't actually need
> to change, and if so a rename would just break it unnecessarily. Any
> votes which way to jump?

It sounds like a good plan, and I'm sure I can adjust either way. Of
course it would be nice if no changes were needed on the PL side unless
they are specifically being changed to take advantage of subtransactions ;-)

Probably the hardest part is to keep the PL code readable while still
supporting cvs tip and 7.4 (and 7.3 for that matter). This is yet
another good example why I think bundling/synchronizing PLs with the
backend is a good thing.

Joe