Content-Type: multipart/alternative;
 boundary="------------ZRfHn8nzAxWJf60DfMsqOcVK"
Message-ID: <c5c90e56-6c66-4125-af11-b4b3eb38aaed@postgrespro.ru>
Date: Tue, 14 Jan 2025 23:35:17 +0300
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: New GUC autovacuum_max_threshold ?
To: Nathan Bossart <nathandbossart@gmail.com>
Cc: Sami Imseih <samimseih@gmail.com>, Robert Treat <rob@xzilla.net>,
 =?UTF-8?Q?Fr=C3=A9d=C3=A9ric_Yhuel?= <frederic.yhuel@dalibo.com>,
 wenhui qiu <qiuwenhuifx@gmail.com>, Robert Haas <robertmhaas@gmail.com>,
 "Imseih (AWS), Sami" <simseih@amazon.com>,
 David Rowley <dgrowleyml@gmail.com>, Joe Conway <mail@joeconway.com>,
 Michael Banck <mbanck@gmx.net>, Laurenz Albe <laurenz.albe@cybertec.at>,
 Melanie Plageman <melanieplageman@gmail.com>,
 PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
References: <Zy-G7u43r1siVkQ6@nathan>
 <2ca7f9c7-5da9-46cb-9072-39b71bfab948@dalibo.com>
 <CAGjGUAKSvvQA583hk-62HyBRhPvowNbhv5+QiRt+znWMA+5OLg@mail.gmail.com>
 <Z32xZZwOi5pXZjYU@nathan> <93f3dab5-caa4-4213-9be0-855d5aaa19bf@dalibo.com>
 <Z37ZlVqUzSapV3ZD@nathan>
 <CABV9wwNxNTEgq0n5DJVDD+mgMbqBJv1-W6R3Dfry4a9C9=z=Uw@mail.gmail.com>
 <Z4AQJYdOsvVHNIbt@nathan> <Z4V1sDjqJ1CnqScY@nathan>
 <CAA5RZ0tAqjtJz+2=S1LvDUJfrpGa73nmLccwvr_R1r8CC4HmaA@mail.gmail.com>
 <Z4XHQR6_AVKiyFjG@nathan>
Content-Language: en-US
From: Alena Rybakina <a.rybakina@postgrespro.ru>
In-Reply-To: <Z4XHQR6_AVKiyFjG@nathan>
Archived-At: <https://www.postgresql.org/message-id/c5c90e56-6c66-4125-af11-b4b3eb38aaed%40postgrespro.ru>
Precedence: bulk

This is a multi-part message in MIME format.
--------------ZRfHn8nzAxWJf60DfMsqOcVK
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit

Hi! Thanks for your work! it is very useful.

On 14.01.2025 05:09, Nathan Bossart wrote:
> On Mon, Jan 13, 2025 at 05:17:11PM -0600, Sami Imseih wrote:
>> I propose renaming the GUC from "autovacuum_max_threshold" to
>> "autovacuum_vacuum_max_threshold" to clarify that it applies only
>> to the vacuum operation performed by autovacuum, not to the analyze operation.
>> This will also align with naming for other related GUCs, i.e.,
>> "autovacuum_analyze_threshold" and "autovacuum_vacuum_threshold."
>>
>> The "vacuum threshold" calculation described in [1] will also need to be
>> updated.
> Good call.  Here is an updated patch.
>
I found one minor mistake in postgresql.conf:

#autovacuum_vacuum_max_threshold = 100000000    # max number of row updates
                         # before vacuum; -1 disables max
                         # threshold

I think instead of "# threshold" should be "#vacuum"?


There is a typo:

* if (threshold > vac_max_thresh)
* threshold = vac_max_thres; - here

I think you should add more information to the description of the 
Relations_needs_vacanalyze function: what is vac_max_thresh and how is 
it calculated. It is not clear what the below condition means.

/* -1 is used to disable max threshold */
vac_max_thresh= (relopts&& relopts->vacuum_max_threshold>= -1)
? relopts->vacuum_max_threshold
: autovacuum_vac_max_thresh;

-- 
Regards,
Alena Rybakina
Postgres Professional

--------------ZRfHn8nzAxWJf60DfMsqOcVK
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: 8bit

<!DOCTYPE html>
<html>
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
  </head>
  <body>
    <p>Hi! Thanks for your work! it is very useful.<br>
    </p>
    <div class="moz-cite-prefix">On 14.01.2025 05:09, Nathan Bossart
      wrote:<br>
    </div>
    <blockquote type="cite" cite="mid:Z4XHQR6_AVKiyFjG@nathan">
      <pre class="moz-quote-pre" wrap="">On Mon, Jan 13, 2025 at 05:17:11PM -0600, Sami Imseih wrote:
</pre>
      <blockquote type="cite">
        <pre class="moz-quote-pre" wrap="">I propose renaming the GUC from "autovacuum_max_threshold" to
"autovacuum_vacuum_max_threshold" to clarify that it applies only
to the vacuum operation performed by autovacuum, not to the analyze operation.
This will also align with naming for other related GUCs, i.e.,
"autovacuum_analyze_threshold" and "autovacuum_vacuum_threshold."

The "vacuum threshold" calculation described in [1] will also need to be
updated.
</pre>
      </blockquote>
      <pre class="moz-quote-pre" wrap="">
Good call.  Here is an updated patch.

</pre>
    </blockquote>
    <p>I found one minor mistake in postgresql.conf:</p>
    <p>#autovacuum_vacuum_max_threshold = 100000000    # max number of
      row updates<br>
                              # before vacuum; -1 disables max<br>
                              # threshold</p>
    <p>I think instead of "# threshold" should be "#vacuum"?</p>
    <p><br>
    </p>
    <p><span style="color: rgb(0, 0, 0); white-space: pre;">There is a typo:</span></p>
    <div><span style="color: #008000;"> * if (threshold &gt;
        vac_max_thresh)</span></div>
    <div><span style="color: #008000;"> * threshold = vac_max_thres; -
        here<br>
      </span></div>
    <p></p>
    <p><span style="color: rgb(0, 0, 0); white-space: pre;">I think you should add more information to the description of the Relations_needs_vacanalyze function: what is vac_max_thresh and how is it calculated. It is not clear what the below condition means.</span><br>
    </p>
    <div
style="color: #000000;background-color: #ffffff;font-family: 'Droid Sans Mono', 'monospace', monospace;font-weight: normal;font-size: 16px;line-height: 22px;white-space: pre;"><div><span
    style="color: #008000;">/* -1 is used to disable max threshold */</span></div><div><span
    style="color: #000000;">    </span><span style="color: #000000;">vac_max_thresh</span><span
    style="color: #000000;"> = (</span><span style="color: #808080;">relopts</span><span
    style="color: #000000;"> &amp;&amp; </span><span
    style="color: #808080;">relopts</span><span style="color: #000000;">-&gt;</span><span
    style="color: #000000;">vacuum_max_threshold</span><span
    style="color: #000000;"> &gt;= -</span><span style="color: #098658;">1</span><span
    style="color: #000000;">)</span></div><div><span
    style="color: #000000;">        ? </span><span
    style="color: #808080;">relopts</span><span style="color: #000000;">-&gt;</span><span
    style="color: #000000;">vacuum_max_threshold</span></div><div><span
    style="color: #000000;">        : </span><span
    style="color: #000000;">autovacuum_vac_max_thresh</span><span
    style="color: #000000;">;</span></div></div>
    <p></p>
    <pre class="moz-signature" cols="72">-- 
Regards,
Alena Rybakina
Postgres Professional</pre>
  </body>
</html>

--------------ZRfHn8nzAxWJf60DfMsqOcVK--