From: Tom Lane <tgl@sss.pgh.pa.us>
To: Kevin Grittner <kgrittn@gmail.com>
cc: Andres Freund <andres@anarazel.de>, Robert Haas <robertmhaas@gmail.com>,
        "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Subject: Re: Implement targetlist SRFs using ROWS FROM() (was Changed SRF in
 targetlist handling)
In-reply-to: 
 <CACjxUsOiFvDxOWi9=3v9-z8YgNN4a5GisDFraKhH0cH1Sn1YBw@mail.gmail.com>
References: <20160523005327.v2tr7obytitxcnna@alap3.anarazel.de>
 <20160822214023.aaxz5l4igypowyri@alap3.anarazel.de>
 <CA+TgmoboLaUy71iLKa2GPcnioWmNxhCFdcDj-F05sZOGgRO0NA@mail.gmail.com>
 <CACjxUsM7PUBF3_u-+J7j1WsoRZ9OVNTw2+=P15t2pqnv7utktQ@mail.gmail.com>
 <20160902141110.6xciuntt5h4i6eni@alap3.anarazel.de>
 <20160902142023.ktgvv4ksnqinqr74@alap3.anarazel.de>
 <10163.1472826300@sss.pgh.pa.us>
 <CACjxUsNrhn5CMk25qsGnx-G6_AAkddQSa=k3g_DFVhb2D1-aSQ@mail.gmail.com>
 <10998.1472827875@sss.pgh.pa.us>
 <CACjxUsOiFvDxOWi9=3v9-z8YgNN4a5GisDFraKhH0cH1Sn1YBw@mail.gmail.com>
Comments: In-reply-to Kevin Grittner <kgrittn@gmail.com>
	message dated "Fri, 02 Sep 2016 10:01:39 -0500"
Date: Fri, 02 Sep 2016 11:10:54 -0400
Message-ID: <11835.1472829054@sss.pgh.pa.us>
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org

Kevin Grittner <kgrittn@gmail.com> writes:
> On Fri, Sep 2, 2016 at 9:51 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> regression=# select *, generate_series(1,3) from int8_tbl;

> I'm sure that you realize that running a query of that form twice
> against a table with more than one heap page could result in rows
> in a different order, even if no changes had been made to the
> database (including no vacuum activity, auto- or otherwise).

You missed my point: they might complain about the generate_series
output not being in the order they expect, independently of what
the table rows are.

Also, before getting too high and mighty with users who expect
"select * from table" to produce rows in a predictable order,
you should reflect on the number of places in our regression
tests that assume exactly that ...

			regards, tom lane


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers