From: Tom Lane <tgl@sss.pgh.pa.us>
To: Alexander Korotkov <aekorotkov@gmail.com>
cc: Robert Haas <robertmhaas@gmail.com>,
        "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Subject: Re: post-freeze damage control
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Comments: In-reply-to Alexander Korotkov <aekorotkov@gmail.com>
	message dated "Tue, 09 Apr 2024 22:47:37 +0300"
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Date: Tue, 09 Apr 2024 16:37:31 -0400
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Alexander Korotkov <aekorotkov@gmail.com> writes:
> On Tue, Apr 9, 2024 at 5:12 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> * OrClauseGroupKey is not a Node type, so why does it have
>> a NodeTag?  I wonder what value will appear in that field,
>> and what will happen if the struct is passed to any code
>> that expects real Nodes.

> I used that to put both not-subject-of-transform nodes together with
> hash entries into the same list.  This is used to save the order of
> clauses.  I think this is an important property, and I have already
> expressed it in [1].

What exactly is the point of having a NodeTag in the struct though?
If you don't need it to be a valid Node, that seems pointless and
confusing.  We certainly have plenty of other lists that contain
plain structs without tags, so I don't buy that the List
infrastructure is making you do that.

			regards, tom lane