Message-ID: <09e2a70a-a6c2-4b5c-aeae-040a7449c9f2@gmail.com>
Date: Mon, 16 Dec 2024 10:00:00 +0200
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Subject: Re: Visibility bug with prepared transaction with subtransactions on
 standby
To: Heikki Linnakangas <hlinnaka@iki.fi>,
 pgsql-hackers <pgsql-hackers@postgresql.org>
Cc: Konstantin Knizhnik <knizhnik@neon.tech>
References: <6b852e98-2d49-4ca1-9e95-db419a2696e0@iki.fi>
 <d4e5f41b-5690-41fb-bf06-e4978393f83a@iki.fi>
 <23c555fb-b4d5-4804-b38f-3082d2d1f522@iki.fi>
Content-Language: en-US
From: Alexander Lakhin <exclusion@gmail.com>
In-Reply-To: <23c555fb-b4d5-4804-b38f-3082d2d1f522@iki.fi>
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Hello Heikki,

27.06.2024 21:35, Heikki Linnakangas wrote:
> All I heard is crickets, so committed and backported to all supported versions.
>

Recently hornet made some noise too: [1], by failing on the test
modification added with e9c8747ee (in REL_13_STABLE):
# issuing query via background psql: SELECT count(*) FROM t_009_tbl_standby_mvcc
# pump_until: process terminated unexpectedly when searching for "(?^:background_psql: QUERY_SEPARATOR)" with stream: ""
query failed: psql:<stdin>:6: ERROR:  relation "t_009_tbl_standby_mvcc" does not exist

It looks like t_009_tbl_standby_mvcc had not arrived to standby yet when
it was queried.

I can reproduce the same with TEMP_CONFIG containing:
recovery_min_apply_delay = '500ms'

All the other tests (I ran check-world) pass with this setting. So maybe
this test lacks waiting for standby synchronization.

[1] https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=hornet&dt=2024-12-13%2022%3A14%3A10

Best regards,
Alexander