MariaDB vs. MySQL

Hi,

i am fighting weird issues with an openjpa application on MariaDB while all
these are non existant on MySQL. Things like "fetch join" are just
different or better said with openjpa 2.2.0 and MariaDB problematic in some
JPQLs.

I even see different SQLs being created from the same JPAQL Queries. Is
this possible at all?

Thanks for infos.