Date: Wed, 9 Dec 2020 19:37:04 +0100
From: Dmitry Dolgov <9erthalion6@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andres Freund <andres@anarazel.de>,
	Pavel Stehule <pavel.stehule@gmail.com>,
	Alexander Korotkov <aekorotkov@gmail.com>,
	Justin Pryzby <pryzby@telsasoft.com>,
	David Steele <david@pgmasters.net>,
	Nikita Glukhov <n.gluhov@postgrespro.ru>,
	Alvaro Herrera <alvherre@2ndquadrant.com>,
	David Fetter <david@fetter.org>,
	Thomas Munro <thomas.munro@gmail.com>,
	Oleksandr Shulgin <oleksandr.shulgin@zalando.de>,
	Robert Haas <robertmhaas@gmail.com>,
	Michael Paquier <michael.paquier@gmail.com>,
	Oleg Bartunov <obartunov@gmail.com>,
	Peter Eisentraut <peter.eisentraut@2ndquadrant.com>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] [PATCH] Generic type subscripting
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> On Wed, Dec 09, 2020 at 12:49:48PM -0500, Tom Lane wrote:
>
> I've pushed the core patch now.

Thanks a lot!

> The jsonb parts now have to be
> rebased onto this design, which I'm assuming Dmitry will tackle

Yes, I'm already on it, just couldn't keep up with the changes in this
thread.

> BTW, while reviewing the thread to write the commit message,
> I was reminded of my concerns around the "is it a container"
> business.  As things stand, if type A has a typelem link to
> type B, then the system supposes that A contains B physically;
> this has implications for what's allowed in DDL, for example
> (cf find_composite_type_dependencies() and other places).
> We now have a feature whereby subscripting can yield a type
> that is not contained in the source type in that sense.
> I'd be happier if the "container" terminology were reserved for
> that sort of physical containment, which means that I think a lot
> of the commentary around SubscriptingRef is misleading.  But I do
> not have a better word to suggest offhand.  Thoughts?

I have only 'a composite'/'a compound' alternative in mind, but it's
probably the same confusing as a container.