Re: bug in SignalSomeChildren

On Fri, Dec 17, 2010 at 10:27 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
>> I think the attached might be a little tidier.  Thoughts?
>
> I'm not really thrilled at the idea of calling
> IsPostmasterChildWalSender for every child whether or not it will have
> any impact on the decision.  That involves touching shared memory which
> can be rather expensive (see previous discussions about shared cache
> lines and so forth).

The existing code already does that, unless I'm missing something.  We
could improve on my proposed patch a bit by doing the is_autovacuum
test first and the walsender test second.  I'm not sure how to improve
on it beyond that.

--
Robert Haas
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