we're running MariaDB on our DB server. We have to install multiple databases on each DB instance (in fact each DB server runs multiple MariaDB instances) because each database must be separated.
We're nearly like an hoster (excepted that we do not provide any file hosting). When you subscribe an hosting plan you often have 1 to X databases and that's what we want to do.
In our company we have 2 DBA: 1 says that we can't have more than 500 DB by instance (due to memory limits) and the 2nd one says that's there's no limitation (excepted FS limitations).
Could you help me to understand or give me some tips (because I'm a project manager and dev. solution need to be chosen and I not a DB expert).