Date: Sun, 4 Feb 2018 09:25:32 -0600
From: Justin Pryzby <pryzby@telsasoft.com>
To: Mariel Cherkassky <mariel.cherkassky@gmail.com>
Cc: Andreas Kretschmer <andreas@a-kretschmer.de>,
	pgsql-performance@lists.postgresql.org
Subject: Re: postgresql 10.1 wrong plan in when using partitions bug
Message-ID: <20180204152532.GT26916@telsasoft.com>
References: 
 <CA+t6e1m54jrEj7spf9ArH5BJiO-Qznn=_YCRGWWMtohvXg7mEg@mail.gmail.com>
 <f042e9cb-be4b-4215-4165-8a14313cbdf7@2ndquadrant.com>
 <CA+t6e1mt-fkvZZX5Wx8B1oPrw=DQOZGr3s=xU_ZhEhKEJtJ-Og@mail.gmail.com>
 <fe3a1929-c843-e10a-8580-302c60db4c13@a-kretschmer.de>
 <CA+t6e1niwYE_F-fpnwFfZNy-Qk9-2RJT5P4F4UTJatLG2iseVg@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: 
 <CA+t6e1niwYE_F-fpnwFfZNy-Qk9-2RJT5P4F4UTJatLG2iseVg@mail.gmail.com>
User-Agent: Mutt/1.5.23 (2014-03-12)
Precedence: bulk

On Sun, Feb 04, 2018 at 05:06:38PM +0200, Mariel Cherkassky wrote:
> Great, it solved the issue. Seems problematic that the planner do full
> scans on all partitions in the first case isnt it ? Seems like a bug ?

See also:
https://www.postgresql.org/message-id/20170725131650.GA30519%40telsasoft.com
https://www.postgresql.org/message-id/20170825154434.GC16287%40telsasoft.com

Justin

2018-02-04 16:54 GMT+02:00 Andreas Kretschmer <andreas@a-kretschmer.de>:
> 
> >
> >
Am 04.02.2018 um 13:19 schrieb Mariel Cherkassky:
> >
> >> I checked the plan of the next query :
> >> explain select count(*) from log_full where end_date between
> >> to_date('2017/12/03','YY/MM/DD') and to_date('2017/12/03','YY/MM/DD');
> >>
> >>
> > can you rewrite the query to
> >
> > ... where end_date between '2017/12/03' and '2017/12/03'
> >
> > maybe the planner should be smart enough to do that for you, but obvously
> > he can't. So it's a workaround, but it seems to solve the problem.