Over at Database Tutorials and Videos, you can read a fascinating excerpt of Nathan Marz's Big Data (partially available now in an early-access edition from Manning). The article covers Marz's innovative new big data methodology that he calls "lambda architecture":
Computing arbitrary functions on an arbitrary dataset in real time is a daunting problem. There is no single tool that provides a complete solution. Instead, you have to use a variety of tools and techniques to build a complete Big Data system.
The lambda architecture solves the problem of computing arbitrary functions on arbitrary data in real time by decomposing the problem into three layers: the batch layer, the serving layer, and the speed layer.
The full article is available at Database Tutorials and Videos and is well worth the read.