Horton

Re: [PATCH] BUG FIX: inconsistent page found in BRIN_REGULAR_PAGE

Alvaro Herrera <alvherre@alvh.no-ip.org>

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From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Karina Litskevich <litskevichkarina@gmail.com>
Cc: 王海洋 <wanghaiyang.001@bytedance.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, pgsql-bugs@lists.postgresql.org
Date: 2022-12-23T16:35:09Z
Lists: pgsql-bugs 
Hello,

On 2022-Dec-23, Karina Litskevich wrote:

> Is there any special reason to read WAL records until the last inserted
> record?

Hmm, no, there's no good reason to do it that way.

> It seems that in some rare situations on slower machines this test can fail.
> If any background process inserts a WAL record before lsn('insert')
> and this record isn't flushed before
> pg_get_wal_records_info('$start_lsn', '$end_lsn'),
> pg_get_wal_records_info('$start_lsn', '$end_lsn') ends with ERROR
> "cannot accept future end LSN" as it works only if record with end LSN
> is inserted.

Hmm.  I've never seen that, but it sounds plausible.

> I attached two patches with two ways of fixing this minor issue.

> -my $end_lsn = $whiskey->lsn('insert');
> +my $end_lsn = $whiskey->lsn('flush');

Thank you, I used this one.

Regards

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/

Commits

  1. Fix end LSN determination in recently added test

  2. BRIN: mask BRIN_EVACUATE_PAGE for WAL consistency checking