The acronym NoSQL was coined in 1998. Many people think that NoSQL is a derogatory term created to spite SQL. In reality, the term means Not Only SQL. The idea is that both technologies can coexist and that each has its place. The NoSQL movement has been in the news in recent years as many Web 2.0 leaders have embraced a NoSQL technology. Companies like Facebook, X (formerly Twitter), Digg, Amazon, LinkedIn, and Google all use NoSQL in one way or another. Let’s break down NoSQL so you can explain it to your CIO or even your coworkers.

Data Storage: The world’s stored digital data is measured in exabytes. An exabyte is equal to one billion gigabytes (GB) of data. According to Internet.com, the amount of stored data added in 2006 was 161 exabytes. Just 4 years later, in 2010, the amount of stored data will be almost 1,000 ExaBytes, an increase of over 500%. In other words, there is a lot of data being stored worldwide and it will only continue to grow.

Interconnected Data: Data is becoming increasingly interconnected. The creation of the web is aided by hyperlinks, blogs have pingbacks, and every major social networking system has tags that connect things together. Large systems are built to be connected.

Complex data structure: NoSQL can handle hierarchical nested data structures easily. To achieve the same in SQL, you need multiple relational tables with all sorts of keys. Also, there is a relationship between performance and data complexity. Performance can suffer in a traditional RDBMS as we store the huge amounts of data required in social networking applications and the semantic web.