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Message-ID: <1a960398-d12d-419a-af48-4acfe58d0c3a@tantorlabs.com>
Date: Wed, 16 Oct 2024 13:31:43 +0300
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Subject: Re: Vacuum statistics
To: Alena Rybakina <a.rybakina@postgrespro.ru>,
 pgsql-hackers <pgsql-hackers@postgresql.org>
Cc: jian he <jian.universality@gmail.com>,
 Alexander Korotkov <aekorotkov@gmail.com>, Andrei Zubkov
 <zubkov@moonset.ru>, Alena Rybakina <lena.ribackina@yandex.ru>,
 a.lepikhov@postgrespro.ru
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From: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com>
In-Reply-To: <30e2e941-b9f6-4ea1-aa3b-f0c406b8797d@postgrespro.ru>
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On 08.10.2024 19:18, Alena Rybakina wrote:
> Made a rebase on a fresh master branch.
> -- 
> Regards,
> Alena Rybakina
> Postgres Professional

Thank you for rebasing.

I have noticed that when I create a table or an index on this table, 
there is no information about the table or index in 
pg_stat_vacuum_tables and pg_stat_vacuum_indexes until we perform a VACUUM.

Example:

CREATE TABLE t (i INT, j INT);
INSERT INTO t SELECT i/10, i/100 FROM  GENERATE_SERIES(1,1000000) i;
SELECT * FROM pg_stat_vacuum_tables WHERE relname = 't';
....
(0 rows)
CREATE INDEX ON t (i);
SELECT * FROM pg_stat_vacuum_indexes WHERE relname = 't_i_idx';
...
(0 rows)

I can see the entries after running VACUUM or executing autovacuum. or 
when autovacuum is executed. I would suggest adding a line about the 
relation even if it has not yet been processed by vacuum. Interestingly, 
this issue does not occur with pg_stat_vacuum_database:

CREATE DATABASE example_db;
SELECT * FROM pg_stat_vacuum_database WHERE dbname = 'example_db';
dboid |       dbname | ...
  ...      | example_db | ...
(1 row)

BTW, I recommend renaming the view pg_stat_vacuum_database to 
pg_stat_vacuum_database_S_  for consistency with pg_stat_vacuum_tables 
and pg_stat_vacuum_indexes

--
Regards,
Ilia Evdokimov,
Tantor Labs LLC.

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    <div class="moz-cite-prefix">On 08.10.2024 19:18, Alena Rybakina
      wrote:<br>
    </div>
    <blockquote type="cite"
      cite="mid:30e2e941-b9f6-4ea1-aa3b-f0c406b8797d@postgrespro.ru">
      <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
      <pre class="tw-data-text tw-text-large tw-ta"
      data-placeholder="Перевод" id="tw-target-text"
      style="text-align:left"
      data-ved="2ahUKEwj_y7mqiv-IAxUAFxAIHZ3EMlIQ3ewLegQIBxAV" dir="ltr"
aria-label="Переведенный текст: Made a rebase on a fresh master branch"><span
      class="Y2IQFc" lang="en">Made a rebase on a fresh master branch.</span></pre>
      <pre class="moz-signature" cols="72">-- 
Regards,
Alena Rybakina
Postgres Professional</pre>
    </blockquote>
    <p>Thank you for rebasing.</p>
    <p>I have noticed that when I create a table or an index on this
      table, there is no information about the table or index in
      pg_stat_vacuum_tables and pg_stat_vacuum_indexes until we perform
      a VACUUM.</p>
    <p>Example:</p>
    <p>CREATE TABLE t (i INT, j INT);<br>
      INSERT INTO t SELECT i/10, i/100 FROM  GENERATE_SERIES(1,1000000)
      i;<br>
      SELECT * FROM pg_stat_vacuum_tables WHERE relname = 't';<br>
      ....<br>
      (0 rows)<br>
      CREATE INDEX ON t (i);<br>
      SELECT * FROM pg_stat_vacuum_indexes WHERE relname = 't_i_idx';<br>
      ...<br>
      (0 rows)</p>
    <p>I can see the entries after running VACUUM or executing
      autovacuum. or when autovacuum is executed. I would suggest adding
      a line about the relation even if it has not yet been processed by
      vacuum. Interestingly, this issue does not occur with
      pg_stat_vacuum_database:</p>
    <p>CREATE DATABASE example_db;<br>
      SELECT * FROM pg_stat_vacuum_database WHERE dbname = 'example_db';<br>
      dboid |       dbname | ...<br>
       ...      | example_db | ...<br>
      (1 row)<br>
      <br>
      BTW, I recommend renaming the view pg_stat_vacuum_database to
      pg_stat_vacuum_database<u>S</u>  for consistency with
      pg_stat_vacuum_tables and pg_stat_vacuum_indexes</p>
    <p>--<br>
      Regards,<br>
      Ilia Evdokimov,<br>
      Tantor Labs LLC.<br>
    </p>
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