I don't know if it's more of a question or a suggestion but here is the thing:

If you have to load a huge amount of datas (let's say 200go on a daily basis) to mariadb server from another, it is way more efficient to copy from source and replace the destination /var/lib/mysql directory (Server may take 5min to start) than dump and then import a gigantic sql file.

when you try to do that in columnstore, you can see tables appear in target db, but when you want to read them, you see "table doesn't exist as columnstore engine" or something like, probably for the same reason you can't alter table innodbt engine=columnstore.

So bask to that, the only way seems to be dump from row mariadb server and import sql file into columnstore server, then create table with engine columnstore equivalent tables but without indexes (show create table can be useful since mariadb columnstore now cover almost all types existing in mariadb) and then do something like insert into columnstore_table select * from row_table.

I read a few about cpimport, but is it something to use with select into outfile?

Is there a real good method to go from row to column here ?

Thank you for your time

Thomas