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Message-ID: <087edd0d-b657-44b9-b0f4-46953894ca36@aklaver.com>
Date: Wed, 16 Oct 2024 11:03:10 -0700
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Subject: Re: Query performance issue
To: yudhi s <learnerdatabase99@gmail.com>,
 pgsql-general <pgsql-general@lists.postgresql.org>
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From: Adrian Klaver <adrian.klaver@aklaver.com>
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On 10/16/24 10:50 AM, yudhi s wrote:
> Hi,
> 
> Below question got in one discussion.Appreciate any guidance on this.
> 
> Below is a query which is running for ~40 seconds. As it's a query which 
> is executed from UI , we were expecting it to finish in <~5 seconds. It 
> has a "IN" and a "NOT IN" subquery , from the execution path it seems 
> the total response time is mainly, to be sum of the "IN" and the "NOT 
> IN" subquery section. My thought was that both "IN" and "NOT IN" should 
> be executed/evaluated in parallel but not in serial fashion.
> 
> In the execution path below , the line number marked in *bold* are the 
> top lines for the IN and NOT IN subquery evaluation and they are showing 
> "Actual time" as  Approx ~9 seconds and ~8 seconds and they seems to be 
> summed up and the top lines showing it to be ~19 seconds. Then onwards 
> it keeps on increasing with other "nested loop" joins.
> 
> *Note*:- This query is running on a MYSQL 8.0 database. So I'm wondering 
> if there is any mysql list similar to Oracle list , in which i can share 
> this issue?
> 

This is the Postgres list.

As to your question maybe one of the forums?:

https://forums.mysql.com/

In particular Performance:

https://forums.mysql.com/list.php?24


-- 
Adrian Klaver
adrian.klaver@aklaver.com