Re: Speed up Clog Access by increasing CLOG buffers

On Wed, Oct 12, 2016 at 3:21 AM, Dilip Kumar <dilipbalaut@gmail.com> wrote:
> I think at higher client count from client count 96 onwards contention
> on CLogControlLock is clearly visible and which is completely solved
> with group lock patch.
>
> And at lower client count 32,64  contention on CLogControlLock is not
> significant hence we can not see any gain with group lock patch.
> (though we can see some contention on CLogControlLock is reduced at 64
> clients.)

I agree with these conclusions.  I had a chance to talk with Andres
this morning at Postgres Vision and based on that conversation I'd
like to suggest a couple of additional tests:

1. Repeat this test on x86.  In particular, I think you should test on
the EnterpriseDB server cthulhu, which is an 8-socket x86 server.

2. Repeat this test with a mixed read-write workload, like -b
tpcb-like@1 -b select-only@9

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company