Horton

Re: Some optimizations for COALESCE expressions during constant folding

Richard Guo <guofenglinux@gmail.com>

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From: Richard Guo <guofenglinux@gmail.com>
To: David Rowley <dgrowleyml@gmail.com>
Cc: Pg Hackers <pgsql-hackers@lists.postgresql.org>
Date: 2025-11-26T11:55:22Z
Lists: pgsql-hackers

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On Tue, Nov 25, 2025 at 10:16 PM David Rowley <dgrowleyml@gmail.com> wrote:
> uhh, of course it is. That's what I did in [1] for Consts. Doing it
> this way means we'll not need to modify the constant folding code (or
> whichever other code wants to know when an Expr can't be NULL) every
> time we think of something new that we can prove can't be NULL.

OK.  Here is an updated patch that does that.  (There is some overlap
in changes to expr_is_nonnullable with the patch you mentioned.)

- Richard