Date: Thu, 14 Feb 2019 04:05:33 -0600
From: Justin Pryzby <pryzby@telsasoft.com>
To: suganthi Sekar <suganthi@uniphore.com>
Cc: "pgsql-performance@lists.postgresql.org"
 <pgsql-performance@lists.postgresql.org>
Subject: Re: constraint exclusion with ineq condition (Re: server hardware
 tuning.)
Message-ID: <20190214100533.GA30291@telsasoft.com>
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On Thu, Feb 14, 2019 at 09:38:52AM +0000, suganthi Sekar wrote:
>  i am using Postgresql 11, i have 2 partition table , when i joined both table in query
> a table  its goes exact partition table  , but other table scan all partition
> 
> please clarify on this .
> 
> Example :
> 
> explain analyze
> select * from call_report1 as a  inner join  call_report2 as b on a.call_id=b.call_id
>  where a.call_created_date ='2017-11-01' and '2017-11-30'

Looks like this query waas manally editted and should say:
>  where a.call_created_date >='2017-11-01' AND a.call_created_date<'2017-11-30'
Right?

The issue is described well here:
https://www.postgresql.org/message-id/flat/7DF51702-0F6A-4571-80BB-188AAEF260DA%40gmail.com
https://www.postgresql.org/message-id/499.1496696552%40sss.pgh.pa.us

You can work around it by specifying the same condition on b.call_created_date:
>  AND b.call_created_date >='2017-11-01' AND b.call_created_date<'2017-11-30'

Justin