What format do sites like Facebook use to store data for personal profiles?

I recently started dealing with large sets of data stored in XML files. I've always wondered how Facebook and other networking sites store all the information associated with individual profiles (name, profile picture, wall posts, etc.) and I feel like XML is definitely not the best way to store so much information. I've tried finding开发者_StackOverflow社区 information about it with google but haven't been having too much luck.

How do huge sites such as Facebook store and deal with so much data? I would really like to do some reading about this, so if you know of any good websites please let me know!

Rather than being stored in an XML file, Facebook uses a relational database--specifically, a modified version of MySQL. If you're interested in their implementation, the MySQL official site has a whole page of articles related to Facebook's MySQL usage at http://www.mysql.com/customers/view/?id=757

Well for storing data under facebook ,they use a new database that is known as "NoSQL" means accessing of data fm DB without having SQL.To know more about it just search for NOSQL in the google. M sure u will definately get ur ans.