Re: LISTEN and "tuple concurrently updated"

On Mon, 15 Sep 2003, Tom Lane wrote:

> Gavin Sherry <swm@linuxworld.com.au> writes:
> > A user on IRC came across the following "tuple concurrently updated" error
> > when using LISTEN/NOTIFY intensively.
>
> I've applied a fix for this to CVS tip.

Great.

> I think that whenever we get around to rewriting LISTEN/NOTIFY to use
> shared memory messages instead of a table, it will be necessary to apply
> listen/unlisten commands that way (hold them until commit) to preserve
> transactional semantics.  But for now, I'm not going to do the extra
> work.

I wasn't thinking about the deadlock/performance problems when I sent in
that patch. It was more a proof of my theory. I was certainly thinking
about the various discussions about reworking LISTEN/NOTIFY into
shared memory when looking at the code, but as you say, its not a job for
right now :-).

Thanks,

Gavin