MariaDB audit plugin logs all queries instead of DML only
As of version 1.4.4 of the plugin, there is now a QUERY_DML_NO_SELECT type that should give you what you are expecting.


  Same as QUERY_DML, but doesn't log SELECT queries. (since version 1.4.4) (DO, CALL, LOAD DATA/XML, DELETE, INSERT, UPDATE, HANDLER and REPLACE statements)


This was introduced in MariaDB 5.5.42, MariaDB 10.0.17, and MariaDB 10.1.4.