Re: Performance comparison between Pgsql 10.5 and Pgsql 11.2

I did a analyze in stages on both.
And Yes both are compiled.
This is the configure command (change 10.6 for PG10)

./configure --prefix=/usr/local/pgsql11.2

See attached perf report. The difference seems to be all in this line, but
not sure :

+ 26.80% 0.00% 222 postmaster [kernel.kallsyms]
[k] system_call_fastpath

I am using CentOS 7
With Centos I am using this profile for tuned-adm
[root(at)STAGING-CMD1 ~]# tuned-adm active
Current active profile: latency-performance

Il giorno sab 2 mar 2019 alle ore 20:41 Thomas Munro <thomas(dot)munro(at)gmail(dot)com>
ha scritto:

> On Sat, Mar 2, 2019 at 5:02 AM Ray O'Donnell <ray(at)rodonnell(dot)ie> wrote:
> > On 01/03/2019 15:01, Nicola Contu wrote:
> > > Hello,
> > > is there any reason why I am getting worse results using pgsql11.2 in
> > > writing comparing it with pgsql 10.6?
> > >
> > > I have two Instances, both just restored, so no bloats.
> > > Running read queries I have pretty much same results, a little bit
> > > better on pg11- Running writes the difference is in favour of 10.
> >
> > Did you run ANALYZE on the databases after restoring?
>
> If you can rule out different query plans, and if you compiled them
> both with the same compiler and optimisation levels and without
> cassert enabled (it's a long shot but I mentioned that because you
> showed a path in /usr/local so perhaps you're hand-compiling 11, but
> 10 came from a package?), then the next step might be to use a
> profiler like "perf" (or something equivalent on your OS) to figure
> out where 11 is spending more time in the write test?
>
> --
> Thomas Munro
> https://enterprisedb.com
>