Why NoSQL Databases Are Gaining Fans

Where MongoDB's calling card has been agility and ease of development, DataStax and Couchbase tout scalability first and foremost. DataStax provides commercial support and implementation consulting for Apache Cassandra, a wide-column NoSQL database initially developed by Facebook and contributed to open source. DataStax's list of Web-scale customers includes Facebook-owned Instagram, which deployed the database last year to help support its 150 million-plus monthly users.

Cassandra is also being embraced by more conventional enterprises, according to DataStax, which claims to have more than 20 Fortune 100 customers (though I can't seem to find them on the company's customer list). Skeptics have said that large companies are typically deploying one of every kind of promising new technology, but that hasn't kept DataStax from touting a new era of database wars.

"We're dealing with enterprises that have done their mission-critical work on Oracle for years, and suddenly they're starting to pick different technologies," DataStax CEO Billy Bosworth told InformationWeek earlier this year.

The scale of applications and nature of applications is changing, asserts Bosworth. Relational databases are fine for internal-facing applications with a few hundred or a few thousand users, but scalability and always-on performance are musts when you're dealing with customer-facing Web applications. Cassandra offers scalability and high availability because it's built for clustered deployments distributed across multiple data centers. Distributed nodes take over for failed nodes within any single cluster, and replicas of the database in any one data center can take over if an entire cluster or data center goes offline.

Couchbase is a key-value database, but last year it introduced JSON (Java Script Object Notation) document-handling capabilities to try to blend the best of both worlds: the scalability and resilience of Cassandra with the ease-of-development and document-handling properties of MongoDB. Marquis customers at Couchbase include LinkedIN, McGraw Hill and Concur.

Given their Web roots, Cassandra, Couchbase and MongoDB have certainly taken more business away from MySQL than any commercially licensed database, but the recent infusions of capital show that there's big money riding on broad enterprise adoption of NoSQL.

As we explain, there are only certain applications for which NoSQL makes sense, but these products are helping many companies pioneer a whole new world of applications that were never before possible to build or easily sustain. You might choose a NoSQL product because it's more scalable, more flexible, more affordable or all of the above. It all depends on the specific type of NoSQL product you're considering and your precise application needs.