View Updating and Relational Theory by Date, C.J. -- Read -- Imperial Library of Trantor

Index

View Updating and Relational Theory Dedication preface About the Author Preface

Who Should Read This Book Structure of the Book Technical Notes Acknowledgments

Foreword 1. A Motivating Example

The Principle of Interchangeability Base Tables Only: Constraints Base Tables Only: Compensatory Actions Views: Constraints and Compensatory Actions There’s No Magic Concluding Remarks

2. The Technical Context

Relations and Relvars

Base Relvar Definitions

Relational Assignment

A Note on Syntax Multiple Assignment Semantics Not Syntax

Integrity Constraints

Updating Is Set At a Time Two Important Principles

Relvar Predicates Matching, not Matching, and Extend Databases and Dbvars

A dbvar is a tuple variable.

3. The View Concept: A Closer Look

The View Update Problem

Views are Pseudovariables Data Independence

Views Serve a Variety of Purposes A Psychological Mistake?

How Not to do it Constraints and Predicates

Multivariable Constraints

Information Equivalence Concluding Remarks

4. Restriction Views

The Motivating Example Revisited More on Compensatory Actions What About Triggers? What About Explicit Update Operations? Suppliers and Shipments The Motivating Example Continued

Information Hiding

Putting it All Together The Point at Last Overlapping Restrictions Concluding Remarks

5. Projection Views

Example 1: A Nonloss Decomposition Example 1 Continued: The Projection Relvars

Information Hiding

Example 1 Continued: Views Example 2: Another Nonloss Decomposition

The Projection Relvars Information Hiding Views

Example 3: A Lossy Decomposition

The Projection Relvars Information Hiding Views

Concluding Remarks

6. Join Views I: One to One Joins

Example 1: Information Equivalence Example 2: Information Hiding

Pragma Symmetry

Concluding Remarks

7. Join Views II: Many to Many Joins

Example 1: Information Equivalence

Compensatory Actions View Updating

Projection Views Revisited Example 2: Information Hiding Concluding Remarks

8. Join Views III: One to Many Joins

Example 1: Information Equivalence Example 2: Information Hiding Concluding Remarks

9. Intersection Views

Example 1: Explicit Overlap Example 2: Implicit Overlap

A Better Design Another Possible Design

Concluding Remarks

10. Union Views

Example 1: Disjoint Union Example 2: Explicit Overlap Example 3: Implicit Overlap

A Better Design A Remark on Disjoint Union

Concluding Remarks

11. Difference Views

Example 1: Implicit Overlap

A Better Design A Remark on Included Difference

Example 2: Explicit Overlap Concluding Remarks

12. Group and Ungroup Views

The Group and Ungroup Operators A Group / Ungroup Example A Summarize Example

13. Extension and Summarization Views

An Extend Example

Relation Constants

Another Summarize Example

14. Updating through Expressions

Semantics not Syntax (?) Some well known Tautologies “Semantic Transformations” Information Equivalence Revisited Concluding Remarks

15. Ambiguity Revisited

Predicates and Constraints Revisited An Intersection Example Union and Difference Examples

Union Difference