From: Venkatesan, Sekhar <sekhar.venkatesan@emc.com>
To: David G. Johnston <david.g.johnston@gmail.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-sql@postgresql.org <pgsql-sql@postgresql.org>
Subject: Re: Question on PostgreSQL DB behavior w.r.t JOIN and sort order.
Date: Tue, 9 Feb 2016 05:48:32 +0000
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Is there a way to tell the optimizer to retain the sort order if that is possible please?
From: David G. Johnston [mailto:david.g.johnston@gmail.com]
Sent: Tuesday, February 09, 2016 11:17 AM
To: Venkatesan, Sekhar
Cc: Tom Lane; pgsql-sql@postgresql.org
Subject: Re: [SQL] Question on PostgreSQL DB behavior w.r.t JOIN and sort order.
On Monday, February 8, 2016, Venkatesan, Sekhar <sekhar.venkatesan@emc.com<mailto:sekhar.venkatesan@emc.com>> wrote:
So from what I understand, you say in postgres, if the sort order is not specified, postgres returns results in any order. Am I right?
Yes. It will optimize for speed without any regard for maintaining any kind of ordering. You may get the desired order for various reasons but without ORDER BY you cannot be guaranteed.
David J.
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To: pgsql-sql@postgresql.org
Cc: sekhar.venkatesan@emc.com, david.g.johnston@gmail.com, tgl@sss.pgh.pa.us
Subject: Re: Question on PostgreSQL DB behavior w.r.t JOIN and sort order.
In-Reply-To: <F84DE43FDACD4C45AA84E2DA016FAE2F1C65BF07@MX105CL01.corp.emc.com>
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