From: Tom Lane <tgl@sss.pgh.pa.us>
To: Desmond Coertzen <patrolliekaptein@gmail.com>
cc: pgsql-sql@postgresql.org
Subject: Re: Subselect left join / not exists()
In-reply-to: 
 <CALQ6=2Bs6K9Qe7NzOCUGGVjVSVszjy5L+wGPGA1a-COn0-8GhQ@mail.gmail.com>
References: 
 <CALQ6=2BRu5P5=u5RE8su_JQhJBj+1b-oSMbuq97d40M4C6iwgQ@mail.gmail.com>
 <32307.1456498805@sss.pgh.pa.us>
 <CALQ6=2AkuawZW=6BvGwj3tJn=rHdtuvgv0WA6LDAU5BRp0ssng@mail.gmail.com>
 <CALQ6=2Cu_pROq6AAw5HZ8Mkon1B6oNPRsap6khpNS2AUAxV7wQ@mail.gmail.com>
 <10339.1457910832@sss.pgh.pa.us>
 <CALQ6=2Bs6K9Qe7NzOCUGGVjVSVszjy5L+wGPGA1a-COn0-8GhQ@mail.gmail.com>
Comments: In-reply-to Desmond Coertzen <patrolliekaptein@gmail.com>
	message dated "Mon, 14 Mar 2016 11:40:56 +0200"
Date: Mon, 14 Mar 2016 09:42:41 -0400
Message-ID: <30076.1457962961@sss.pgh.pa.us>
Precedence: bulk
Sender: pgsql-sql-owner@postgresql.org

Desmond Coertzen <patrolliekaptein@gmail.com> writes:
> I was under the impression that postgres will not allow me to declare a
> function immutable if it falls outside of the bounds of the definition.

IIRC, there was an explicit decision not to throw errors for "immutable
function reads a table", because we have no way to be sure that such a
thing might not be safe in practice in a particular usage.  (That is,
you actually don't ever change the table's contents after first use of
the function.)  But yeah, it's a gray area.

			regards, tom lane


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