Re: [PATCH] Improve performance of NOTIFY over many databases (v2)

Martijn van Oosterhout <kleptog@gmail.com> writes:
> On Mon, 16 Sep 2019 at 15:33, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> But do we care?  With asyncQueueAdvanceTail gone from the listeners,
>> there's no longer an exclusive lock for them to contend on.  And,
>> again, I failed to see any significant contention even in HEAD as it
>> stands; so I'm unconvinced that you're solving a live problem.

> You're right, they only acquire a shared lock which is much less of a
> problem. And I forgot that we're still reducing the load from a few
> hundred signals and exclusive locks per NOTIFY to perhaps a dozen
> shared locks every thousand messages. You'd be hard pressed to
> demonstrate there's a real problem here.

> So I think your patch is fine as is.

OK, pushed.

> Looking at the release cycle it looks like the earliest either of
> these patches will appear in a release is PG13, right?

Right.

            regards, tom lane