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> 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.