Re: Performance comparison between Pgsql 10.5 and Pgsql 11.2

Because I have 10.6 in production :) and I am comparing with what I will be
loosing.
And I read that in the release notes but as said in my first email, even
with data_sync_retry=on (going back to previous behavior) doesn't make any
difference.

So I am looking for something that will keep my performances but still
allows me to upgrade to 11 in production.
Also, trying with 11.1, the problem seems still there.

Il giorno lun 4 mar 2019 alle ore 14:45 Imre Samu <pella(dot)samu(at)gmail(dot)com> ha
scritto:

> > is there any reason why I am getting worse results using pgsql11.2 in
> writing comparing it with pgsql 10.6?
> >... And Yes both are compiled.
>
> Why 10.6?
>
> according to release notes
> "14th February 2019: PostgreSQL 11.2, 10.7, 9.6.12, 9.5.16, and 9.4.21
> Released!" https://www.postgresql.org/about/news/1920/
> imho:* it would be better to compare PG11.2 with PG10.7 *( similar
> bug Fixes and Improvements + same fsync() behavior )
>
> *"This release changes the behavior in how PostgreSQL interfaces with
> fsync() and includes fixes for partitioning and over 70 other bugs that
> were reported over the past three months"*
>
> Imre
>
>
>
> Nicola Contu <nicola(dot)contu(at)gmail(dot)com> ezt írta (időpont: 2019. márc. 4.,
> H, 13:14):
>
>> 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
>>>
>>