Unable to set join_buffer_size to a negative value (-0.95M) in the config file

[fabioamd87]

hello guys,
when I try to set join_buffer_size in /etc/mysql/mariadb.conf.d/50-server.cnf on my raspberry pi 2 with Raspbian GNU/Linux 11 (bullseye) to satisfy the following requirement:

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join_buffer_size	1 M	<=	-0.95 M	When performing joins, if they are below this size, they will be kept in memory and never written to a temporary file. As this is a per connection memory allocation, care must be taken not to increase it too high. The sum of the join_buffer_size + sort_buffer_size + read_buffer_size + read_rnd_buffer_size + thread_stack + binlog_cache_size + Core MySQL/MariaDB memory should be below 80%. If the recommendation is negative, you must decrease this and or the sort_buffer_size until the recommendation fits within the allowable memory.

I get the following error:

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Jul 16 14:25:36 raspy systemd[1]: Starting MariaDB 10.5.23 database server...
Jul 16 14:25:37 raspy mariadbd[18065]: Unknown suffix '.' used for variable 'join_buffer_size' (value '-0.95M')
Jul 16 14:25:37 raspy mariadbd[18065]: 2024-07-16 14:25:37 0 [Warning] option 'join_buffer_size': unsigned value 0 adjusted to 128
Jul 16 14:25:37 raspy mariadbd[18065]: 2024-07-16 14:25:37 0 [ERROR] /usr/sbin/mariadbd: Error while setting value '-0.95M' to 'join_buffer_size'
Jul 16 14:25:37 raspy systemd[1]: mariadb.service: Main process exited, code=exited, status=1/FAILURE
Jul 16 14:25:37 raspy systemd[1]: mariadb.service: Failed with result 'exit-code'.
Jul 16 14:25:37 raspy systemd[1]: Failed to start MariaDB 10.5.23 database server.

how to set a negative value?

Thanks.

[cigamit]

Did you not read all the text in the description?

If the recommendation is negative, you must decrease this and or the sort_buffer_size until the recommendation fits within the allowable memory.

What do you have sort_buffer_size set as?

[fabioamd87]

to be honest I read quickly that statement too, but I was not sure what kind of calculation I had to do.

I didn't fine sort_buffer_size string in the default config file.

Thanks!

[TheWitness]

Which mean's it's the default.