From: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
Subject: Re: Domains and arrays and composites, oh my
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@postgresql.org
References: <4206.1499798337@sss.pgh.pa.us> <12364.1499973554@sss.pgh.pa.us>
 <aaaa73ea-4d5f-ed8c-7222-06a2d5f2891e@2ndQuadrant.com>
 <32440.1506618167@sss.pgh.pa.us>
Message-ID: <044f3a1c-9e20-c08b-8f78-c47aa41d7a0c@2ndQuadrant.com>
Date: Thu, 28 Sep 2017 14:58:00 -0400
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.3.0
MIME-Version: 1.0
In-Reply-To: <32440.1506618167@sss.pgh.pa.us>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Content-Language: en-MW
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org


On 09/28/2017 01:02 PM, Tom Lane wrote:
>
>> I do think that treating a function returning a domain-over-composite
>> differently from one returning a base composite is a POLA. We'd be very
>> hard put to explain the reasons for it to an end user.
> Do you have any thoughts about how we ought to resolve that?
>
>


Not offhand. Maybe we need to revisit the decision not to modify the
executor at all. Obviously that would make the patch a good deal more
invasive ;-(  One thought I had was that we could invent a new return
type of TYPEFUNC_DOMAIN_COMPOSITE so there would be less danger of a PL
just treating it as an unconstrained base type as it might do if it saw
TYPEFUNC_COMPOSITE.

Maybe I'm wrong, but I have a strong suspicion that of we leave it like
this now we'll regret it in the future.

cheers

andrew

-- 
Andrew Dunstan                https://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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