Re: Performance degradation in commit ac1d794

On Thu, Feb 11, 2016 at 12:53 PM, Andres Freund <andres(at)anarazel(dot)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