Personally I feel you need to define your database requirements; and feed that into the emergent chat.
for example if you want your database to run on pgsql - say so.
or if you want to run in a TLS encrypted mysql 8.0 database configured with a multi-master backend - again just say that is what you want.
I've asked for emergent to use external databases (that i built in AWS, and another in CloudFlare), providing API keys etc and declaring them as variables. Worked perfectly.