Re: Speed up Clog Access by increasing CLOG buffers

On Tue, Sep 20, 2016 at 9:15 AM, Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
> +1
>
> My test are under run, I will post it soon..

I have some more results now....

8 socket machine
10 min run(median of 3 run)
synchronous_commit=off
scal factor = 300
share buffer= 8GB

test1: Simple update(pgbench)

Clients Head GroupLock
32 45702 45402
64 46974 51627
128 35056 55362

test2: TPCB (pgbench)

Clients Head GroupLock
32 27969 27765
64 33140 34786
128 21555 38848

Summary:
--------------
At 32 clients no gain, I think at this workload Clog Lock is not a problem.
At 64 Clients we can see ~10% gain with simple update and ~5% with TPCB.
At 128 Clients we can see > 50% gain.

Currently I have tested with synchronous commit=off, later I can try
with on. I can also test at 80 client, I think we will see some
significant gain at this client count also, but as of now I haven't
yet tested.

With above results, what we think ? should we continue our testing ?

--
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com