Message-ID: <3f1b817f-6e7a-4e01-bfc5-50ea3724225e@uni-muenster.de>
Date: Fri, 29 Nov 2024 20:12:44 +0100
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Subject: Re: Truncate logs by max_log_size
To: Kirill Gavrilov <diphantxm@gmail.com>
Cc: Kirill Reshke <reshkekirill@gmail.com>,
 "Andrey M. Borodin" <x4mmm@yandex-team.ru>, Euler Taveira
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From: Jim Jones <jim.jones@uni-muenster.de>
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On 29.11.24 12:05, Kirill Gavrilov wrote:
>   Setting max_log_size to 0 already disables truncation.
>   I changed guc units to bytes, just to make it more human-friendly.
> Did some refactoring and fixed all warnings. Set default value in
> postgresql.conf.

Nice. The patch applies cleanly and the warnings are gone.

A few other things:

IMHO the documentation can be a bit clearer. It says to input the values
in bytes, but the default value is in megabytes.

+        If greater than zero, each query logged is truncated to this
many bytes.
+        Zero disables the setting.
+        Default value is 5MB.

Perhaps something like "If this value is specified without units, it is
taken as bytes." (see wal_keep_size)

And a pedantic note: This hint suggests that you can use TB as unit ..

postgres=# set max_log_size = '1foo';
ERROR:  invalid value for parameter "max_log_size": "1foo"
HINT:  Valid units for this parameter are "B", "kB", "MB", "GB", and "TB".

.. but it can never be used, as it exceeds the integer range:

postgres=# SET max_log_size = '1TB';
ERROR:  invalid value for parameter "max_log_size": "1TB"
HINT:  Value exceeds integer range.

Thanks

-- 
Jim