As part of the Big Data Lecture Series -- Fall 2012, Google’s Chris Olston gave a talk on how to manage processing of large data sets. In this talk he gives an overview of his work on large-scale data processing at Yahoo! Research. He begins his talk by introducing two data processing systems: Pig, a dataflow programming environment and Hadoop-based runtime, and Nova, a workflow manager for Pig/Hadoop. Rest of the talk focuses on debugging, and looks at what can be done before, during and after execution of a data processing operation.