Mongo DB is a new age no SQL datastore which is gaining traction. Mongo DB is also opensource (http://www.mongodb.org/) . MongoDB is a scalable, high-performance, open source, document-oriented database. Written in C++.
The NoSQL data store is now being used to archive billions of records at Craigslist, the popular classifieds and job posting community that serves 570 cities in 50 countries.
Here are some basic numbers about the Craigslist MongoDB cluster from Jeremy Zawodny, one of the site’s software engineers:
Weâ€™re sizing the install for around 5 billion documents. Thatâ€™s from the initial 2 billion document import we need to do plus room to grow for a few years to come. Average document size is right around 2KB. (Five billion 2KB documents is 10TB of data.) Weâ€™re getting our feet wet with MongoDB so this particular task isnâ€™t high throughput or growing in unpredictable ways.
We can put data into MongoDB faster than we can get it out of MySQL during the migration.