Horton

Re: Domains and arrays and composites, oh my

Andrew Dunstan <andrew.dunstan@2ndquadrant.com>

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From: Andrew Dunstan <andrew.dunstan@2ndquadrant.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: pgsql-hackers@postgresql.org
Date: 2017-09-28T18:58:00Z
Lists: pgsql-hackers 

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

Commits

  1. Support domains over composite types in PL/Perl.

  2. Support domains over composite types in PL/Tcl.

  3. Support domains over composite types.

  4. Fix multiple assignments to a column of a domain type.