Message-ID: <e6d20179-ddbd-3376-a7f5-4831df7d6b60@gmail.com>
Date: Sun, 7 Jan 2024 22:00:00 +0300
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Subject: Re: [BUG] false positive in bt_index_check in case of short 4B
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To: "Andrey M. Borodin" <x4mmm@yandex-team.ru>,
 Michael Zhilin <m.zhilin@postgrespro.ru>
Cc: pgsql-bugs@postgresql.org, y sokolov <y.sokolov@postgrespro.ru>
References: <7bdbe559-d61a-4ae4-a6e1-48abdf3024cc@postgrespro.ru>
 <0FDE2089-D306-4CBB-AD1F-EC4B419E3B33@yandex-team.ru>
From: Alexander Lakhin <exclusion@gmail.com>
In-Reply-To: <0FDE2089-D306-4CBB-AD1F-EC4B419E3B33@yandex-team.ru>
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Hello Andrey,

07.01.2024 21:04, Andrey M. Borodin wrote:
>> On 14 Dec 2023, at 21:18, Michael Zhilin <m.zhilin@postgrespro.ru> wrote:
> I've checked that:
> * bug is reproduced by the test in the patch
> * bug is fixed by the patch
> * fix seems idiomatic, similar to nearby code
>

What is your opinion regarding similar failures, which are not addressed
by the patch? Besides the case shown above, there is another one:
CREATE TABLE tbl(i int4, t text);
ALTER TABLE tbl ALTER COLUMN t SET STORAGE plain;
CREATE INDEX tbl_idx ON tbl (t, i) WITH (fillfactor = 10);
INSERT INTO tbl SELECT g, repeat('Test', 250) FROM generate_series(1, 130) g;
ALTER TABLE tbl ALTER COLUMN t SET STORAGE extended;

CREATE EXTENSION amcheck;
SELECT bt_index_check('tbl_idx', true);

ERROR:  heap tuple (0,1) from table "tbl" lacks matching index tuple within index "tbl_idx"
HINT:  Retrying verification using the function bt_index_parent_check() might provide a more specific error.

Best regards,
Alexander