Re: Performance degradation in commit ac1d794 - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Performance degradation in commit ac1d794
Date
Msg-id CA+TgmoaYuAbFviV2CvFkct9k3wGR+cVdyOMUnS=c=ZPG0aDD7w@mail.gmail.com
Whole thread Raw
In response to Re: Performance degradation in commit ac1d794  (Andres Freund <andres@anarazel.de>)
Responses Re: Performance degradation in commit ac1d794
List pgsql-hackers
On Thu, Feb 11, 2016 at 12:53 PM, Andres Freund <andres@anarazel.de> wrote:
>> One problem is that it makes for misleading results if you try to
>> benchmark 9.5 against 9.6.
>
> You need a really beefy box to show the problem. On a large/new 2 socket
> machine the performance regression in in the 1-3% range for a pgbench of
> SELECT 1. So it's not like it's immediately showing up for everyone.
>
> Putting it on the open items list sounds good to me.

Well, OK, I've done that then.  I don't really agree that it's not a
problem; the OP said he saw a 3x regression, and some of my colleagues
doing benchmarking are complaining about this commit, too.  It doesn't
seem like much of a stretch to think that it might be affecting other
people as well.

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



pgsql-hackers by date:

Previous
From: Tom Lane
Date:
Subject: Re: GinPageIs* don't actually return a boolean
Next
From: Robert Haas
Date:
Subject: Re: [PATCH v4] GSSAPI encryption support