When i do simple SQL statemens 'example: select * from table' the metabase.db.mv.db will be extemely big. nearly 4GB.
Than the metabase will be extremely slow. The result is, i have to take the old db-backup and restore it.
I use the latest Version, but i'm not very happy with it.
I usually create another user for metabase with only read access to only required tables/views. MB may try to investigate all the columns of all the tables in the db in the background.
H2 isn’t recommeded for live, only test. I don’t know anything about iSeries, but you need to think about having a Linux or Windows server running MySQL to store Metabase’s data. Would only need to be a tiny VM.