Cassandra: The Definitive Guide

Chapter 1. Introducing Cassandra

If at first the idea is not absurd, then there is no hope for it.

—Albert Einstein

Welcome to Cassandra: The Definitive Guide. The aim of this book is to help developers and database administrators understand this important new database, explore how it compares to the relational database management systems we’re used to, and help you put it to work in your own environment.

What’s Wrong with Relational Databases?

If I had asked people what they wanted, they would have said faster horses.

—Henry Ford

I ask you to consider a certain model for data, invented by a small team at a company with thousands of employees. It is accessible over a TCP/IP interface and is available from a variety of languages, including Java and web services. This model was difficult at first for all but the most advanced computer scientists to understand, until broader adoption helped make the concepts clearer. Using the database built around this model required learning new terms and thinking about data storage in a different way. But as products sprang up around it, more businesses and government agencies put it to use, in no small part because it was fast—capable of processing thousands of operations a second. The revenue it generated was tremendous.

And then a new model came along.

The new model was threatening, chiefly for two reasons. First, the new model was very different from the old model, which it pointedly controverted. It was threatening because it can be hard to understand ...