Re: [HACKERS] Performance issue with postgres9.6 - Mailing list pgsql-hackers

From Merlin Moncure
Subject Re: [HACKERS] Performance issue with postgres9.6
Date
Msg-id CAHyXU0ybttO3tybbzxahnnk9pw9L6U=SezwAOHFiVyg70Jh+Uw@mail.gmail.com
Whole thread Raw
In response to [HACKERS] Performance issue with postgres9.6  (Prakash Itnal <prakash074@gmail.com>)
Responses Re: [HACKERS] Performance issue with postgres9.6  (Tomas Vondra <tomas.vondra@2ndquadrant.com>)
List pgsql-hackers
On Fri, Apr 7, 2017 at 5:16 AM, Prakash Itnal <prakash074@gmail.com> wrote:
> Hello,
>
> We currently use psotgres 9.3 in our products. Recently we upgraded to
> postgres 9.6. But with 9.6 we have seen a drastic reduction in throughput.
> After analyzing carefully I found that "planner time" in 9.6 is very high.
> Below are the details:
>
> Scenario:
> 1 Create a table with 100000 rows.
> 2 Execute simple query: select * from subscriber where s_id = 100;
> 3 No update/delete/insert; tried vacuum, full vacuum; by default we enable
> auto-vacuum
>
> 9.3: Avg of "Total runtime" : 0.24ms [actual throughput: 650 TPS]
> 9.6: Avg of Total time: 0.56ms (Avg of "Planning time" : 0.38ms + Avg of
> "Execution time" : 0.18ms) [actual throughput: 80 TPS]

I think your math is off.  Looking at your attachments, planning time
is 0.056ms, not 0.56ms.  This is in no way relevant to performance on
the order of your measured TPS.   How are you measuring TPS?

merlin



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