Data Crunching looks at some of the tasks that IT people have to do from time to time: extracting and transforming text fragments from files, database extracts, and much more. He shows us how he would attack the problem using the best tool for the job. Even if you don't have access to all of the tools in your environment, you can still gain insight in how he attacks the problem, provides the documentation he believes necessary ('one-time' hacks have been known to run for years), and how to modify it when bugs are found or he needs to enhance it.
I liked his style of commentary, as thought processes are often more important in problem solving than the code written. I also liked how he bounced from manipulating text files, to regular expressions, to database extracts, to binary manipulation. Many of the problems IT people need to solve are peripheral to their main area of expertise, and these diverse subjects illustrate that nicely.
I rate the book a 7.5 out of 10. Well done.