I have written a math game in Java, and have distributed some copies to a few beta-testers. The problem is that the version I have given them is saving the GameData via object serialization, which I found out is mainly for sending Objects, or in this case, ArrayLists of GameData, over a network. It is NOT persistance; that is what a relational database is for. Knowing this, I would like to know if it would be better to create a database on the beta-tester's machine (and rewrite the game), or continue with the Object serialization version of the game, and then retrieve the Objects when they are ready to send the data?
My guess would be to just move their data to a database that is created on their computer, and then give them the database version of the game. That way, the data can be persisted and be much easier to manipulate. What turns me away from that idea is the question of how am I going to write their database into mine (in the future)?
Although relatively rare, there are still lots of applications that use serialization for storage and retrieval of objects. It's not wrong to do this, just slightly unusual. If it's working for you, stick with it because DB's are a heavyweight solution. What you found out, about serialization, is only an opinion and an ill-formed one at that.