Book Image

Data Analysis Using SQL and Excel - Second Edition

By : Gordon S. S. Linoff
Book Image

Data Analysis Using SQL and Excel - Second Edition

By: Gordon S. S. Linoff

Overview of this book

Data Analysis Using SQL and Excel, 2nd Edition shows you how to leverage the two most popular tools for data query and analysis—SQL and Excel—to perform sophisticated data analysis without the need for complex and expensive data mining tools. Written by a leading expert on business data mining, this book shows you how to extract useful business information from relational databases. You'll learn the fundamental techniques before moving into the "where" and "why" of each analysis, and then learn how to design and perform these analyses using SQL and Excel. Examples include SQL and Excel code, and the appendix shows how non-standard constructs are implemented in other major databases, including Oracle and IBM DB2/UDB. The companion website includes datasets and Excel spreadsheets, and the book provides hints, warnings, and technical asides to help you every step of the way. Data Analysis Using SQL and Excel, 2nd Edition shows you how to perform a wide range of sophisticated analyses using these simple tools, sparing you the significant expense of proprietary data mining tools like SAS.
Table of Contents (18 chapters)
Free Chapter
1
Foreword
17
EULA

Time Windowing

Time windows are more than just the solution to left truncation. They are a powerful technique for other purposes. This section investigates time windows in general and some ways to use them.

A Business Problem

Once upon a time, a mobile phone company was developing a forecasting application using survival analysis. This type of application was discussed in the previous chapter, and forecasting can be a powerful application of survival analysis. They provided a large amount of data for tens of millions of customers early one May for a proof-of-concept. The schedule called for the proof-of-concept to be reviewed in the summer, steadily improved upon, and then the final forecasting project would begin at the end of the year. So, using historical data, the proof-of-concept began that May.

In April, a shrewd person in finance decided to change one of the company’s policies, just a little tweak actually. The old policy was to disconnect a customer on the date the customer...