You are previewing View Updating and Relational Theory.
O'Reilly logo
View Updating and Relational Theory

Book Description

Views are a key part of database technology, but they're often considered read-only. In this book, Chris Date—a leading expert in relational databases—offers practical techniques that allow you to update the views that a database presents to you.

Table of Contents

  1. View Updating and Relational Theory
  2. Dedication
  3. preface
  4. About the Author
  5. Preface
    1. Who Should Read This Book
    2. Structure of the Book
    3. Technical Notes
    4. Acknowledgments
  6. Foreword
  7. 1. A Motivating Example
    1. The Principle of Interchangeability
    2. Base Tables Only: Constraints
    3. Base Tables Only: Compensatory Actions
    4. Views: Constraints and Compensatory Actions
    5. There’s No Magic
    6. Concluding Remarks
  8. 2. The Technical Context
    1. Relations and Relvars
      1. Base Relvar Definitions
    2. Relational Assignment
      1. A Note on Syntax
      2. Multiple Assignment
      3. Semantics Not Syntax
    3. Integrity Constraints
      1. Updating Is Set At a Time
      2. Two Important Principles
    4. Relvar Predicates
    5. Matching, not Matching, and Extend
    6. Databases and Dbvars
      1. A dbvar is a tuple variable.
  9. 3. The View Concept: A Closer Look
    1. The View Update Problem
      1. The View Update Problem
    2. Views are Pseudovariables
    3. Data Independence
      1. Views Serve a Variety of Purposes
      2. A Psychological Mistake?
    4. How Not to do it
    5. Constraints and Predicates
      1. Multivariable Constraints
    6. Information Equivalence
    7. Concluding Remarks
  10. 4. Restriction Views
    1. The Motivating Example Revisited
    2. More on Compensatory Actions
    3. What About Triggers?
    4. What About Explicit Update Operations?
    5. Suppliers and Shipments
    6. The Motivating Example Continued
      1. Information Hiding
    7. Putting it All Together
    8. The Point at Last
    9. Overlapping Restrictions
    10. Concluding Remarks
  11. 5. Projection Views
    1. Example 1: A Nonloss Decomposition
    2. Example 1 Continued: The Projection Relvars
      1. Information Hiding
    3. Example 1 Continued: Views
    4. Example 2: Another Nonloss Decomposition
      1. The Projection Relvars
      2. Information Hiding
      3. Views
    5. Example 3: A Lossy Decomposition
      1. The Projection Relvars
      2. Information Hiding
      3. Views
    6. Concluding Remarks
  12. 6. Join Views I: One to One Joins
    1. Example 1: Information Equivalence
    2. Example 2: Information Hiding
      1. Pragma
      2. Symmetry
    3. Concluding Remarks
  13. 7. Join Views II: Many to Many Joins
    1. Example 1: Information Equivalence
      1. Compensatory Actions
      2. View Updating
    2. Projection Views Revisited
    3. Example 2: Information Hiding
    4. Concluding Remarks
  14. 8. Join Views III: One to Many Joins
    1. Example 1: Information Equivalence
    2. Example 2: Information Hiding
    3. Concluding Remarks
  15. 9. Intersection Views
    1. Example 1: Explicit Overlap
    2. Example 2: Implicit Overlap
      1. A Better Design
      2. Another Possible Design
    3. Concluding Remarks
  16. 10. Union Views
    1. Example 1: Disjoint Union
    2. Example 2: Explicit Overlap
    3. Example 3: Implicit Overlap
      1. A Better Design
      2. A Remark on Disjoint Union
    4. Concluding Remarks
  17. 11. Difference Views
    1. Example 1: Implicit Overlap
      1. A Better Design
      2. A Remark on Included Difference
    2. Example 2: Explicit Overlap
    3. Concluding Remarks
  18. 12. Group and Ungroup Views
    1. The Group and Ungroup Operators
    2. A Group / Ungroup Example
    3. A Summarize Example
  19. 13. Extension and Summarization Views
    1. An Extend Example
      1. Relation Constants
    2. Another Summarize Example
  20. 14. Updating through Expressions
    1. Semantics not Syntax (?)
    2. Some well known Tautologies
    3. “Semantic Transformations”
    4. Information Equivalence Revisited
    5. Concluding Remarks
  21. 15. Ambiguity Revisited
    1. Predicates and Constraints Revisited
    2. An Intersection Example
    3. Union and Difference Examples
      1. Union
      2. Difference
    4. More on Predicates
    5. Concluding Remarks
  22. A. Some Remarks on Relational Assignment
  23. B. Relational Operators
  24. Index
  25. About the Author
  26. Copyright