Storing data client data

I am making a l开发者_运维百科ittle light weight 2 way chat client, however I am unsure how to store the data my options are:

• JSON
• XML
• Text File
• Database

I will be using PHP and Ajax, which would be scalable and small in size?

Since you are trying to develop a Chat client, performance here is key.

i would suggest the following (my personal favorite):

Server Side

1. Store Data in Database for a nice balance between performance and flexibility
2. PHP page that interacts as an interface between the Database and the client via JSON since it's lightweight and therefore fast

Client Side

1. AJAX based GUI that can parse and send JSON data.
2. (Optional) use a JavaScript framework to help you with #1, like jQuery/ExtJS/etc'

If you would like to choose this set up I would also suggest you at least familiarize yourself with the other options so you can decide for your own.

Good Luck!