The Apache Cassandra database 2.0.3 has been released. As a vastly scalable open source
NoSQL database, Cassandra is perfect for maintaining huge lists of
structured, semi-structured, and unstructured data with maximum
flexibility and fast response times . It works across multiple data
centers and the cloud and delivers linear scalability and
performance. Once Cassandra completes storing data it will survive permanently, even if the server is killed or crashes or loses power. So , it does not allow even a single point of failure.
Being NoSQL database , Cassandra has its own mechanism for querying named Cassandra Query Language (CQL) which is a SQL (Structured Query Language)-like language for querying
Cassandra. It's data model offers an index on column values for efficient querying just as like as SQL and you define tables, with
columns and associated data types. However, an important difference is that since Cassandra is designed for distributed system, it emphasizes Denormalization more than Normalization and Joins, and
provides tools like collections to support this.
Its logs structured storage engine avoids random i/o and it has powerful built-in caching.You can read more about there in here
As Netflix users says "I can create a Cassandra cluster in any region of the world in 10 minutes. When marketing guys decide we wan to move into a certain part of the world , we'er ready ". Lot's of big companies like
Netflix,
eBay,
Twitter ,
Reddit etc are using Cassandra
So why not you ?
