Re: [HACKERS] Increase Vacuum ring buffer. - Mailing list pgsql-hackers

From Stephen Frost
Subject Re: [HACKERS] Increase Vacuum ring buffer.
Date
Msg-id 20170720193744.GO1769@tamriel.snowman.net
Whole thread Raw
In response to Re: [HACKERS] Increase Vacuum ring buffer.  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-hackers
* Robert Haas (robertmhaas@gmail.com) wrote:
> On Thu, Jul 20, 2017 at 3:04 PM, Stephen Frost <sfrost@snowman.net> wrote:
> > I agree that it's a common problem for VACUUM to go too fast, or for
> > VACUUM to go too slow, but that's really what the vacuum_cost_limit
> > mechanism is for.
>
> I think that's a valid point.  There are also other concerns here -
> e.g. whether instead of adopting the patch as proposed we ought to (a)
> use some smaller size, or (b) keep the size as-is but reduce the
> maximum fraction of shared_buffers that can be consumed, or (c) divide
> the ring buffer size through by autovacuum_max_workers.  Personally,
> of those approaches, I favor (b).  I think a 16MB ring buffer is
> probably just fine if you've got 8GB of shared_buffers but I'm
> skeptical about it when you've got 128MB of shared_buffers.

Right, agreed on that and that (b) looks to be a good option there.

Thanks!

Stephen

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