[Koha] Character sets in MariaDB 10.5

[Michael Kuhn]

Hi

1. In the last few years when installing Koha on Debian GNU/Linux 9 or 
10 the character sets in MariaDB were as follows:

MariaDB [(none)]> SHOW VARIABLES LIKE '%char%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8mb4                    |
| character_set_connection | utf8mb4                    |
| character_set_database   | utf8mb4                    |
| character_set_filesystem | binary                     |
| character_set_results    | utf8mb4                    |
| character_set_server     | utf8mb4                    |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+

Today I installed Koha 21.05.03 on Debian GNU/Linux 11 with MariaDB 
10.5.11 where the character sets are as follows:

MariaDB [(none)]> SHOW VARIABLES LIKE '%char%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | utf8mb4                    |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | utf8mb4                    |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+

I'm not sure what is going on here. Does anyone know why the character 
sets for client, connection and results have changed from utf8mb4 to 
utf8? Is this correct with Koha or should these character sets be changed?

2. Today I came upon an installation of Koha 18.11.05 using MariaDB 
10.0.32 which has the following character sets:

MariaDB [(none)]> SHOW VARIABLES LIKE '%char%';
+--------------------------+----------------------------+
| Variable_name            | Value                      |
+--------------------------+----------------------------+
| character_set_client     | utf8                       |
| character_set_connection | utf8                       |
| character_set_database   | latin1                     |
| character_set_filesystem | binary                     |
| character_set_results    | utf8                       |
| character_set_server     | latin1                     |
| character_set_system     | utf8                       |
| character_sets_dir       | /usr/share/mysql/charsets/ |
+--------------------------+----------------------------+

This seems quite wrong to me - as far as I know "latin1" was never a 
supported character set in Koha... as far as I know the character sets 
should be set as shown in topic 1.

However, is it still possible to update such a database with these 
character sets to Koha 21.05.03 without destroying the data completely?

Best wishes: Michael
-- 
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