From: Rihad <grihad@gmail.com>
To: Adrian Klaver <adrian.klaver@aklaver.com>
To: pgsql-general General <pgsql-general@postgresql.org>
Subject: Re: Why doesn't autovacuum/analyze run in due time after calling pg_stat_reset?
Date: Sun, 20 Aug 2023 23:10:33 +0400
Message-ID: <c1d7097c-710a-9513-7831-c765a2b622bf@gmail.com> (raw)
In-Reply-To: <9440ab9c-4ee1-7668-5476-dc28e8086524@aklaver.com>
References: <69eacc0a-7e9b-4a35-278b-110b93d72882@mail.ru>
<18167fbd-815f-9b43-7016-5e5bbb8fb255@gmail.com>
<9440ab9c-4ee1-7668-5476-dc28e8086524@aklaver.com>
On 8/20/23 20:22, Adrian Klaver wrote:
> On 8/18/23 22:35, Rihad wrote:
>> On 8/17/23 13:01, rihad wrote:
>>>
>>> Hi, all. After calling pg_stat_reset all statistics used by
>>> autovacuum got zeroed, and started accumulating from scratch. Some
>>> tables get acted upon properly, some don't.
>>>
>>>
>> Self-replying: yup, it seems there's an arbitrary limit of 100K of
>> n_live_tup after which autovac/analyze kicks in, or it seems so.
>
> To know rather then guess read:
>
> https://www.postgresql.org/docs/current/routine-vacuuming.html#AUTOVACUUM
Sure, I read it before asking.
Taking the first table in the list as an example:
relname | n_live_tup | n_dead_tup | left |
n_mod_since_analyze | left
--------------------------+------------+------------+----------+---------------------+--------
fooooooooooo | 32781 | 240663 | -234057 |
513265 | -509937
n_dead_tup (not the actual value, but some time after calling
pg_stat_reset) is much larger than 20% of n_live_tup 32781, and
n_mod_since_analyze is much larger than 10% of it.
Yet it is kept unvacuumed and unanalyzed for a long time.
autovacuum_(vacuum|analyze)_threshold is 50.
What am I missing?
>
>>
>> There are still many tables waiting for their turn, which is long due.
>>
>> Although there are some tables having only 60-70 (not 60-70K)
>> n_live_tup that have had autovacuum run on them. Weird.
>>
>>
>>
>
>
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To: pgsql-general@postgresql.org
Cc: grihad@gmail.com, adrian.klaver@aklaver.com
Subject: Re: Why doesn't autovacuum/analyze run in due time after calling pg_stat_reset?
In-Reply-To: <c1d7097c-710a-9513-7831-c765a2b622bf@gmail.com>
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