"Within the first 6 pages, you'll get the concept and start seeing applications in your own work. This book has all the detail you need to get you through simple and complicated uses of hash objects. You'll be surprised that you had not known how to use hash tables before. They are a particularly important tool for those using large data sets who want to speed up simple operations. And, if you run into code with hash object programming, this book will provide everything you need to understand and modify it."

Peter Graven
Research Faculty, Center for Health Systems Effectiveness
Oregon Health and Science University

"I knew this book was written for me when I read the opening sentence, ‘Programming hash objects in SAS sounds like a geeky process,’ and then immediately saw examples using DATA step merge, PROC SQL, and the hash object to present problems and show how the hash object fits in the solution space. The book starts with a no-nonsense approach that continues throughout, illustrating all the concepts with clear examples. I recommend this book to anyone who needs to learn how to effectively use the hash object. If you have a limited time budget, the clear examples will quickly show you how the hash objects work. When your time budget expands, you can revisit the book to learn why the hash object works as it does."

Peter Eberhardt
Fernwood Consulting Group

"This book instructs and guides SAS programmers on how to use SAS hash objects to gain efficiencies in matching, merging, manipulating, and creating SAS data sets. For those unfamiliar with component objects such as hash tables, the book is a thorough introduction, offering clear explanations of elements associated with object-oriented programming and contrasting them to familiar SAS concepts such as array processing, sorting, and match/merging. In this way, it promotes the advantages of using hash tables as opposed to hard-coding data modifications or attempting to sort or index very large data sets that are not optimally organized. The author does not attempt to educate her audience in basic SAS principles, but instead leverages the audience’s knowledge while introducing the new material.

At the same time it demonstrates their efficacy, the book states the dependence of hash objects on available memory. Tips on estimating the amount of space your hash object might require, and how to conserve memory and still get the job done are stated at the beginning of the book.

The author also uses her SAS savvy to emphasize specific methods when more than one way of performing a task exists. For example, declaring and instantiating the hash object can be done two different ways; precise examples in the book work through the second method

More complex features of hash objects such as their dynamic properties are covered in the latter chapters of the book. Precisely illustrated examples of hash objects with and without multiple set of data items per key value are cast using data examples that SAS programmers frequently encounter, making the material accessible and immediately relevant.

Because hash object programming is often counterintuitive and is complex both conceptually and syntactically, the author’s guidance through dozens of applied examples makes the book an invaluable resource. Readers who learn well from examples will find the book to be effective training. At the same time it offers practical examples, it also does an admirable job of covering the underlying principles of objects and their associated properties and methods."

Pat Bland
OptumHealth

The opinions expressed are those of the reviewer only, and do not reflect the opinion of OptumHealth or United Health Group.

"If you are a SAS programmer who is ready to advance your programming skills, you should check out Michele's latest book about hash objects in SAS! Being able to use look-up tables is so basic for many SAS programming projects. Adding hash object programming to your DATA step arsenal can make your programming more efficient and more powerful than other look-up methods you are already familiar with (formats, merges, joins, etc.). Michele explains how to get started using hash object programming in SAS. She steps through typical examples to show you how, why, and when to do it. She might even convince you that hash object programming can actually be more easily programmed for complex look-ups than techniques you are already familiar with now."

Sue Hakomaki
OptumHealth

The opinions expressed are those of the reviewer only, and do not reflect the opinion of OptumHealth or United Health Group.