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

From Tom Lane
Subject Re: [HACKERS] Performance issue with postgres9.6
Date
Msg-id 16541.1491587697@sss.pgh.pa.us
Whole thread Raw
In response to Re: [HACKERS] Performance issue with postgres9.6  (Tomas Vondra <tomas.vondra@2ndquadrant.com>)
Responses Re: [HACKERS] Performance issue with postgres9.6  (Merlin Moncure <mmoncure@gmail.com>)
List pgsql-hackers
Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
> On 04/07/2017 06:31 PM, Merlin Moncure wrote:
>> 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?

> Not sure where did you get the 0.056ms?

I don't see that either, but:

> What I see is this in the 9.3 explains:
>   Total runtime: 0.246 ms
> and this in those from 9.6:
>   Planning time: 0.396 ms
>   Execution time: 0.181 ms
> That is roughly 0.25ms vs. 0.6ms (0.4+0.2), as reported by Prakash.

9.3's EXPLAIN did not measure planning time at all.  The "Total runtime"
it reports corresponds to "Execution time" in the newer version.  So
these numbers indicate that 9.6 is significantly *faster*, not slower,
than 9.3, at least so far as execution of this one example is concerned.

The OP may well be having some performance issue with 9.6, but the
presented material completely fails to demonstrate it.
        regards, tom lane



pgsql-hackers by date:

Previous
From: Andres Freund
Date:
Subject: Re: [HACKERS] recent deadlock regression test failures
Next
From: Robert Haas
Date:
Subject: Re: [HACKERS] UPDATE of partition key