C. J. Date

View Updating and Relational Theory (eBook, PDF)

Solving the View Update Problem

• Format: PDF

Produktbeschreibung

Views are virtual tables. That means they should be updatable, just as "e;real"e; or base tables are. In fact, view updatability isnt just desirable, its 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 dont 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 futureHelp with a "e;roll your own"e; implementation, absent such product improvementsMake you aware of the crucial role of predicates and constraintsShow you how relational products are really supposed to behaveAnyone with a professional interest in the relational model, relational technology, or database systems in general can benefit from this book.

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Produktdetails

• Verlag: O'Reilly Media
• Seitenzahl: 260
• Erscheinungstermin: 20. Dezember 2012
• Englisch
• ISBN-13: 9781449357825
• Artikelnr.: 38311023

Autorenporträt

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.

Inhaltsangabe

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