http://www.velir.com/blog/index.php/2014/06/03/xdb-sitecore-dms-moves-to-mongodb/
http://www.sitecore.net/About/Press-and-Media/Press-Releases/2014/05/MongoDB.aspx
Some of the benefits that Sitecre is aiming to achieve by moving to MongoDB are,
- Scalability
- Speed/Performance
- High Availability
- Flexibility with the Data model
About MongoDB
MongoDB is the leading NoSQL database, empowering businesses to be more agile and scalable.
MongoDB is built for scalability, performance and high availability, scaling from single server deployments to large, complex multi-site architectures.
Quote : https://www.mongodb.com/mongodb-overview
To achieve high scalability and speed, MongoDB has cut down (removed) some features in RDBMs. Few features that MongoDB does not deal with are,
- Joins
- Complex Transactions
MongoDB provides some online training/certification programs, which I think very good to learn about MongoDB.
https://university.mongodb.com
I have started to follow "M102: MongoDB for DBAs" training program from MongoDB university. Even though I am in the beginner level when it comes to MongoDB, I have already started to love this new database. :-)