Re: Speed up Clog Access by increasing CLOG buffers - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: Speed up Clog Access by increasing CLOG buffers
Date
Msg-id CAA4eK1JHBmkUmWK1vNsBD4qD+EhuAf3FkVDt0r0rxAJc9aTN+A@mail.gmail.com
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In response to Re: Speed up Clog Access by increasing CLOG buffers  (Robert Haas <robertmhaas@gmail.com>)
Responses Re: Speed up Clog Access by increasing CLOG buffers
List pgsql-hackers
On Thu, Nov 3, 2016 at 8:38 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> On Tue, Nov 1, 2016 at 11:31 PM, Tomas Vondra
>> The difference is that both the fast-path locks and msgNumLock went into
>> 9.2, so that end users probably never saw that regression. But we don't know
>> if that happens for clog and WAL.
>>
>> Perhaps you have a working patch addressing the WAL contention, so that we
>> could see how that changes the results?
>
> I don't think we do, yet.
>

Right.  At this stage, we are just evaluating the ways (basic idea is
to split the OS writes and Flush requests in separate locks) to reduce
it.  It is difficult to speculate results at this stage.  I think
after spending some more time (probably few weeks), we will be in
position to share our findings.

-- 
With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com



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