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Subject: Re: dshash_find_or_insert vs. OOM
From: Chao Li <li.evan.chao@gmail.com>
In-Reply-To: 
 <CA+TgmoYc1PG27ySdjX+fv85-iXA-qNj-AybxQAE7kseKv+qdLQ@mail.gmail.com>
Date: Thu, 19 Mar 2026 08:08:26 +0800
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>,
 Andres Freund <andres@anarazel.de>,
 Thomas Munro <thomas.munro@gmail.com>
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To: Robert Haas <robertmhaas@gmail.com>
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> On Mar 19, 2026, at 01:46, Robert Haas <robertmhaas@gmail.com> wrote:
>=20
> On Tue, Mar 17, 2026 at 9:34=E2=80=AFPM Chao Li =
<li.evan.chao@gmail.com> wrote:
>> When OOM happens, Assert((flags & DSHASH_INSERT_NO_OOM) !=3D 0); =
makes sense. But for resize(), the assert is inside resize(), while for =
insert_into_bucket(), the assert is in the caller. That feels a bit =
inconsistent to me, and I think it hurts readability a little. A reader =
might wonder why there is no corresponding assert after resize() unless =
they go read the function body.
>=20
> Adjusted.
>=20
>> Making this a nested block does have the benefit of keeping dsa_flags =
close to where it is used. But from my impression, this style is still =
fairly uncommon in the codebase. I worry it may implicitly signal to =
other hackers that this is an acceptable pattern. So unless we =
intentionally want to encourage that style, I would lean toward avoiding =
it here.
>=20
> Yeah, that was dumb. Fixed.
>=20
> Thanks for the review; here's v2.
>=20
> --=20
> Robert Haas
> EDB: http://www.enterprisedb.com
> <v2-0001-dshash-Make-it-possible-to-suppress-out-of-memory.patch>

Thanks for updating the patch. V2 LGTM.

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