Re: constraint exclusion with ineq condition (Re: server hardware tuning.)

From: Michael Lewis <mlewis(at)entrata(dot)com>
To: suganthi Sekar <suganthi(at)uniphore(dot)com>
Cc: Justin Pryzby <pryzby(at)telsasoft(dot)com>, "pgsql-performance(at)lists(dot)postgresql(dot)org" <pgsql-performance(at)lists(dot)postgresql(dot)org>
Subject: Re: constraint exclusion with ineq condition (Re: server hardware tuning.)
Date: 2019-02-14 18:50:00
Message-ID: CAHOFxGrosn+yrSwOB8wVBjFbbn=gSD6C2psKCVbno3dYHQZXvA@mail.gmail.com
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Yeah, the planner doesn't know that call_created_date can be limited on
both tables unless you tell it specify it in the where condition as Laurenz
said on another thread.

*Michael Lewis*

On Thu, Feb 14, 2019 at 7:35 AM suganthi Sekar <suganthi(at)uniphore(dot)com>
wrote:

> Both table Portion by same column call_created_date
> ________________________________
> From: Michael Lewis <mlewis(at)entrata(dot)com>
> Sent: 14 February 2019 19:35:48
> To: suganthi Sekar
> Cc: Justin Pryzby; pgsql-performance(at)lists(dot)postgresql(dot)org
> Subject: Re: constraint exclusion with ineq condition (Re: server hardware
> tuning.)
>
> What are these two tables partitioned by?
>
> On Thu, Feb 14, 2019, 5:03 AM suganthi Sekar <suganthi(at)uniphore(dot)com
> <mailto:suganthi(at)uniphore(dot)com> wrote:
> Hi,
>
> Thanks, i know if explicitly we give in where condition it is working.
>
> i thought with below parameter in Postgresq11 this issue is fixed ?
>
> enable_partitionwise_join to 'on';
>
> what is the use of enable_partitionwise_join to 'on';
>
> Thanks for your response.
>
> Regards
> Suganthi Sekar
> ________________________________
> From: Justin Pryzby <pryzby(at)telsasoft(dot)com<mailto:pryzby(at)telsasoft(dot)com>>
> Sent: 14 February 2019 16:10:01
> To: suganthi Sekar
> Cc: pgsql-performance(at)lists(dot)postgresql(dot)org<mailto:
> pgsql-performance(at)lists(dot)postgresql(dot)org>
> Subject: Re: constraint exclusion with ineq condition (Re: server hardware
> tuning.)
>
> On Thu, Feb 14, 2019 at 10:38:36AM +0000, suganthi Sekar wrote:
> > u mean the below parameter need to set on . its already on only.
> > alter system set constraint_exclusion to 'on';
>
> No, I said:
> > 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'
>

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