This document summarizes Cassandra, an open source distributed database management system designed to handle large amounts of data across many commodity servers. It discusses Cassandra's history, key features like tunable consistency levels and support for structured and indexed columns. Case studies describe how companies like Digg, Twitter, Facebook and Mahalo use Cassandra to handle terabytes o
![The Cassandra Distributed Database](https://cdn-ak-scissors.b.st-hatena.com/image/square/ffa6bd681e88bbb9de9226ae18355e3611545ed1/height=288;version=1;width=512/https%3A%2F%2Fcdn.slidesharecdn.com%2Fss_thumbnails%2Fpresentation-100210112534-phpapp02-thumbnail.jpg%3Fwidth%3D640%26height%3D640%26fit%3Dbounds)