As far as I understand how MTA and database function as a whole, you should have permanent data on a database (sqlite for instance) and load them into the RAM (select queries) by using tables, global variables, or classes as you wish, whenever the resource stops (or server shuts down) you will want to get the data stored in RAM to be sent to the server to save in the database, so it stays permanent.
Having player data in client's RAM is logically better because it avoids never-ending database requests (this would be rough), you should only request data from the database if needed (i.e. avoid INSERT's or UPDATE's everytime).
