From: Tom Lane <tgl@sss.pgh.pa.us>
To: Richard Guo <guofenglinux@gmail.com>
cc: Alvaro Herrera <alvherre@alvh.no-ip.org>, kyzevan23@mail.ru,
        PostgreSQL mailing lists <pgsql-bugs@lists.postgresql.org>
Subject: Re: BUG #17561: Server crashes on executing row() with very long
 argument list
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Comments: In-reply-to Richard Guo <guofenglinux@gmail.com>
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Date: Fri, 29 Jul 2022 12:57:49 -0400
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Richard Guo <guofenglinux@gmail.com> writes:
> The patch looks good to me. Just wondering if there are any other types
> of expressions that need to check for MaxTupleAttributeNumber in
> parse_expr.c.

As far as I can think, sub-SELECTs and ROW constructs are the only
SQL that can produce composites of non-pre-determined types.
For constructs producing named composite types, the limit on the
number of columns in a table should take care of it.

What I'm more troubled by is whether there are any ways to produce
a wide tuple that don't come through either the parser or a table
definition.  Not sure what that could look like, other than C code
randomly constructing a RowExpr or some such.

			regards, tom lane