Re: LISTEN/NOTIFY and notification timing guarantees

Merlin Moncure <mmoncure@gmail.com> writes:
> On Tue, Feb 16, 2010 at 10:38 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> 2. Add an extra lock to serialize writers to the queue, so that messages
>> are guaranteed to be added to the queue in commit order. �As long as

> fwiw, I think you're definitely on the right track.  IMO, any scenario
> where an issued notification ends up being deferred for an indefinite
> period of time without alerting the issuer should be avoided if at all
> possible.  Just to clarify though, does your proposal block all
> notifiers if any uncommitted transaction issued a notify?

It will block other notifiers until the transaction releases its locks,
which should happen pretty promptly --- there are no user-accessible
reasons for it to wait.
        regards, tom lane