Message database design in a chat app

I'm working on a Chat App. You can chat with one person or create(join) a group. I'm considering how the database should be to store all messages.

I come up with two solutions:

Solution 1. Store all messages to one table;

Solution 2. Create a message database for every person or group that user joined.

Solution 1 is easy to achieve, but I don't know if it keep a good performance as the message grows.

The app runs on iOS and I'll use sqlite database. Any advice would be appreciated. Thanks in advance.