From: Venkatesan, Sekhar <sekhar.venkatesan@emc.com>
To: Adrian Klaver <adrian.klaver@aklaver.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 06:14:41 +0000
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My concern here is that I want to maintain consistency ( in our application to retain sort order) between different databases.
I don't see the issue in SQL Server and Oracle databases.
"SELECT KH_.r_object_id, KH_.object_name FROM dbo.dm_location_s AS ZS_ INNER JOIN
dbo.dm_sysobject_s AS KH_ ON ZS_.r_object_id = KH_.r_object_id "
The above query is sorted based on the first column in the select list. Same is not happening in PostgreSQL.
Is this something to do with collation setting in database?
-----Original Message-----
From: Adrian Klaver [mailto:adrian.klaver@aklaver.com]
Sent: Tuesday, February 09, 2016 11:32 AM
To: Venkatesan, Sekhar; David G. Johnston
Cc: Tom Lane; pgsql-sql@postgresql.org
Subject: Re: [SQL] Question on PostgreSQL DB behavior w.r.t JOIN and sort order.
On 02/08/2016 09:53 PM, Venkatesan, Sekhar wrote:
> Yes. is there an option/configuration to tell the postgres
> optimizer/planner to generate plans to include the sort order instead
> of speed?
What columns in a table would that be and then what order?
>
> *From:*David G. Johnston [mailto:david.g.johnston@gmail.com]
> *Sent:* Tuesday, February 09, 2016 11:20 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:
>
> Is there a way to tell the optimizer to retain the sort order if that
> is possible please?
>
> You mean, besides the ORDER BY clause?
>
> David J.
>
--
Adrian Klaver
adrian.klaver@aklaver.com
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Cc: sekhar.venkatesan@emc.com, adrian.klaver@aklaver.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: <F84DE43FDACD4C45AA84E2DA016FAE2F1C65BF60@MX105CL01.corp.emc.com>
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