Re: [PATCH] Fix null pointer dereference in PG19 - Mailing list pgsql-hackers

Paul A Jungwirth <pj@illuminatedcomputing.com> writes:
> On Tue, Apr 21, 2026 at 8:24 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Checking this at parse time is completely the wrong thing.
>> The view could have gained (or lost) triggers by the time
>> it's executed.

> But INSTEAD OF triggers are selected in the rewriter, which uses the
> same relcache snapshot as parse analysis. And a concurrent change
> can't sneak in different triggers, because that causes a relcache
> invalidation, so we redo the parse & rewrite phases.

You have forgotten about views and rewrite rules.  Those go to disk in
post-parser form, and will be rewritten only at execution sometime
later, *without* a re-parse.

            regards, tom lane