Re: postgres 9.3 vs. 9.4

----- Original Message -----
> From: "Mark Kirkwood" <mark.kirkwood@catalyst.net.nz>
> To: "Tigran Mkrtchyan" <tigran.mkrtchyan@desy.de>
> Cc: "Merlin Moncure" <mmoncure@gmail.com>, "postgres performance list" <pgsql-performance@postgresql.org>
> Sent: Friday, September 19, 2014 8:26:27 AM
> Subject: Re: [PERFORM] postgres 9.3 vs. 9.4
>
> On 19/09/14 17:53, Mkrtchyan, Tigran wrote:
> >
> >
> > ----- Original Message -----
> >> From: "Mark Kirkwood" <mark.kirkwood@catalyst.net.nz>
>
> >> Further to the confusion, here's my 9.3 vs 9.4 on two M550 (one for 9.3
> >> one for 9.4), see below for results.
> >>
> >> I'm running xfs on them with trim/discard enabled:
> >>
> >> $ mount|grep pg
> >> /dev/sdd4 on /mnt/pg94 type xfs (rw,discard)
> >> /dev/sdc4 on /mnt/pg93 type xfs (rw,discard)
> >>
> >>
> >> I'm *not* seeing any significant difference between 9.3 and 9.4, and the
> >> numbers are both about 2x your best number, which is food for thought
> >> (those P320's should toast my M550 for write performance...).
> >
> > cool! any details on OS and other options? I still get the same numbers
> > as before.
> >
>
> Sorry, Ubuntu 14.04 on a single socket i7 3.4 Ghz, 16G (i.e my workstation).
>
> I saw the suggestion that Didier made to run 9.3 on the SSD that you
> were using for 9.4, and see if it suddenly goes slow - then we'd know
> it's something about the disk (or filesystem/mount options). Can you
> test this?


swapping the disks did not change the results.
Nevertheless, I run the same test on my fedora20 laptop
8GB RAM, i7 2.2GHz and got 2600tps! I am totally
confused now! Is it kernel version? libc?


Tigran.
>
> Cheers
>
> Mark
>