In the old days, enterprises really only had three choices for databases: Oracle, Microsoft SQL Server or MySQL. But today, a whole host of new NoSQL databases are trading away some of the power of a relational database in order to provide the speed and scalability that developers need for modern applications.
This lengthy article takes a look at seven NoSQL options — Cassandra, CouchDB, MongoDB, Redis, Riak, Neo4J, and FlockDB ? and analyzes their strengths and weaknesses. It concludes, “All of the packages are relatively stable and useful — for the right projects. But none of them are as feature-rich or sophisticated as the best commercial SQL tools.”