Re: post-freeze damage control

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].  That could be achieved without adding NodeTag to
hash entries, but that would require a level of indirection.  It's not
passed to code that expects real Nodes, it doesn't go to anything
except lists.

Links.
1. https://www.postgresql.org/message-id/CAPpHfdutHt31sdt2rfU%3D4fsDMWxf6tvtnHARgCzLY2Tf21%2Bfgw%40mail.gmail.com

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Regards,
Alexander Korotkov