View Updating and Relational Theory: Solving the View Update Problem

by Chris Date

Overview

Views are virtual tables. That means they should be updatable, just as "real" or base tables are. In fact, view updatability isn’t just desirable, it’s crucial, for practical reasons as well as theoretical ones. But view updating has always been a controversial topic. Ever since the relational model first appeared, there has been widespread skepticism as to whether (in general) view updating is even possible.

In stark contrast to this conventional wisdom, this book shows how views, just like base tables, can always be updated (so long as the updates don’t violate any integrity constraints). More generally, it shows how updating always ought to work, regardless of whether the target is a base table or a view. The proposed scheme is 100% consistent with the relational model, but rather different from the way updating works in SQL products today.

This book can:

• Help database products improve in the future
• Help with a "roll your own" implementation, absent such product improvements
• Make you aware of the crucial role of predicates and constraints
• Show you how relational products are really supposed to behave

Anyone with a professional interest in the relational model, relational technology, or database systems in general can benefit from this book.

Product Details

ISBN-13:	9781449357849
Publisher:	O'Reilly Media, Incorporated
Publication date:	01/09/2013
Pages:	258
Product dimensions:	6.90(w) x 9.10(h) x 0.70(d)

About the Author

C.J. Date has a stature that is unique within the database industry. C.J. is a prolific writer, and is well-known for his best-selling textbook: An Introduction to Database Systems (Addison Wesley). C.J. is an exceptionally clear-thinking writer who can lay out principles and theory in a way easily understood by his audience.

Table of Contents

• preface
• About the Author
• Preface
• Foreword
• Chapter 1: A Motivating Example
• Chapter 2: The Technical Context
• Chapter 3: The View Concept: A Closer Look
• Chapter 4: Restriction Views
• Chapter 5: Projection Views
• Chapter 6: Join Views I: One to One Joins
• Chapter 7: Join Views II: Many to Many Joins
• Chapter 8: Join Views III: One to Many Joins
• Chapter 9: Intersection Views
• Chapter 10: Union Views
• Chapter 11: Difference Views
• Chapter 12: Group and Ungroup Views
• Chapter 13: Extension and Summarization Views
• Chapter 14: Updating through Expressions
• Chapter 15: Ambiguity Revisited
• Some Remarks on Relational Assignment
• Relational Operators