From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | Martijn van Oosterhout <kleptog(at)gmail(dot)com> |
Cc: | pgsql-hackers(at)postgresql(dot)org |
Subject: | Re: [PATCH] Improve performance of NOTIFY over many databases (v2) |
Date: | 2019-09-22 15:48:07 |
Message-ID: | 10226.1569167287@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-hackers |
Martijn van Oosterhout <kleptog(at)gmail(dot)com> writes:
> On Mon, 16 Sep 2019 at 15:33, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)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
From | Date | Subject | |
---|---|---|---|
Next Message | Tom Lane | 2019-09-22 16:28:02 | Re: Wrong sentence in the README? |
Previous Message | Jeff Janes | 2019-09-22 15:45:05 | Re: WAL recycled despite logical replication slot |