How many different databases should I use?

Hello All!

The app I’m building will serve several markets, which I’m implementing one at a time.

If I use a separate database for each market’s posts, should I also use a separate database for Users based on their market? I’m trying to keep this as clean as possible but not sure which is the most logical way - 2 databases per Market or 1 User database for the entire app along with 1 separate Posts database per Market.

Any suggestions are greatly appreciated.

Thanks

Willia