# Error 'Character set '#255' is not a compiled ch aracter set and is not specified in the '/usr/local/mariadb10/share/mysql/charse ts/Index.xml' file' on query. Default database: 'wordpress'. Query: 'BEGIN'

This could be a serious problem when replicating between MySQL 8.0 and MariaDB 10.x.

The default (for good technical reasons) COLLATION for the 8.0 is utf8mb4_0900_ai_ci. Note the "255" associated with it. MariaDB has not yet adopted the Unicode 9.0 collations.

Furthermore, Oracle (MySQL 8.0) did a major rewrite of the collation code, thereby possibly making collation tables incompatible.

probable fix is to switch to the next best general-purpose collation, utf8mb4_unicode_520_ci (246) (based on Unicode 5.20). This would require ALTERing all the columns' collations. ALTER TABLE .. CONVERT TO .. might be the fastest way. Those could be generated via a SELECT .. information_schema.tables ....

8.0.17: