Re: LISTEN and "tuple concurrently updated" - Mailing list pgsql-hackers

From Gavin Sherry
Subject Re: LISTEN and "tuple concurrently updated"
Date
Msg-id Pine.LNX.4.58.0309161022400.14143@linuxworld.com.au
Whole thread Raw
In response to Re: LISTEN and "tuple concurrently updated"  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
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


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