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Subject: Re: updates for handling optional argument in system functions
From: Chao Li <li.evan.chao@gmail.com>
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Date: Wed, 8 Apr 2026 10:09:51 +0800
Cc: Mark Wong <markwkm@gmail.com>,
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 "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>
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To: "David G. Johnston" <david.g.johnston@gmail.com>
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> On Apr 8, 2026, at 09:46, David G. Johnston =
<david.g.johnston@gmail.com> wrote:
>=20
> On Tuesday, April 7, 2026, Chao Li <li.evan.chao@gmail.com> wrote:
>=20
> We can clearly see ":expr {FUNCEXPR :funcid 1573 =E2=80=9C.
>=20
> With this patch, will that view break? How would users find all such =
broken views? Maybe PostgreSQL already has some recommended way to =
handle this kind of situation that I am not aware of?
>=20
> pg_dump resolves oid=3D1573 and produces a textual SQL representation, =
which is then executed during pg_restore.  This happens manually, and =
also automatically by pg_upgrade.  Since the text form hasn=E2=80=99t =
changed the view is still valid in v19.  You would see the new oid if =
inspecting the rule after the upgrade.
>=20
> So yes, the public serialization format being SQL and thus mandatory =
new object creation during upgrade is the way PostgreSQL handles =
implementation detail isolation.
>=20
> David J.
>=20

Hi David, thanks for the explanation, I really didn=E2=80=99t know that.

Then, the patch looks good to me. GET_PRETTY_FLAGS(false) returns =
PRETTYFLAG_INDENT, so no behavior change either.

Best regards,
--
Chao Li (Evan)
HighGo Software Co., Ltd.
https://www.highgo.com/