What conversation about cloud computing is complete without a mention of big data, distributing processing, and distributed databases? There is a recent trend away from relying exclusively on the traditional relational database for everything. Newer technologies like BigTable and Hadoop provide an alternative mechanism for storing and processing large sets of data that don't necessarily have extensive relationships needing modeling. These technologies allow for a much more scalable solution.
In fact, they help in two ways: one by allowing an application to process more data using horizontal scalability (aka 'elasticity') and two by reducing load on the primary relational database and hence allowing you to go longer before 'sharding'.
Chris Wensel is the man when it comes to understanding Hadoop and he recently gave a couple of talks introducing Hadoop. Here is one of them:
