Redis (http://redis.io) is a key-value store and more. It offers facilities very different than relational databases. As a NoSQL database, one has to employ a different philosophy, such as duplicating keys across stores, maintaining reverse lookup, and so on.
In this recipe, we will be using redis to create key-value stores, sorted sets, and hash sets. We will be using the hedis library to connect to Redis and manipulate the data.