Database Design for Mere Mortals: 25th Anniversary Edition

  Information     35
    Null     37
    The Value of Null     38
    The Problem with Null     39
Structure-Related Terms     41
    Table     41
    Field     44
    Record     45
    View     46
    Keys     48
    Index     50
Relationship-Related Terms     50
    Relationships     50
    Types of Relationships     52
    Types of Participation     57
    Degree of Participation     57
Integrity-Related Terms     59
    Field Specification     59
    Data Integrity     59
Summary     61
Review Questions     62
PART II:  THE DESIGN PROCESS     65
Chapter 4:  Conceptual Overview     67
Topics Covered in This Chapter     67
The Importance of Completing the Design Process     68
Defining a Mission Statement and Mission Objectives     69
Analyzing the Current Database     70
Creating the Data Structures     72
Determining and Establishing Table Relationships     73
Determining and Defining Business Rules     74
Determining and Defining Views     75
Reviewing Data Integrity     75
Summary     77
Review Questions     78
Chapter 5:  Starting the Process     81
Topics Covered in This Chapter     81
Conducting Interviews     82
    Participant Guidelines     84
    Interviewer Guidelines (These Are for You)     86
Defining the Mission Statement     91
    The Well-Written Mission Statement     91
    Composing a Mission Statement     93
Defining the Mission Objectives     96
    Well-Written Mission Objectives     97
    Composing Mission Objectives     99
Summary     103
Review Questions     104
Chapter 6:  Analyzing the Current Database     107
Topics Covered in This Chapter     107
Getting to Know the Current Database     107
    Paper-Based Databases     111
    Legacy Databases     111
Conducting the Analysis     113
Looking at How Data Is Collected     113
Looking at How Information Is Presented     116
Conducting Interviews     120
    Basic Interview Techniques     121
    Before You Begin the Interview Process     128
Interviewing Users     128
    Reviewing Data Type and Usage     129
    Reviewing the Samples     131
    Reviewing Information Requirements     135
Interviewing Management     143
    Reviewing Current Information Requirements     144
    Reviewing Additional Information Requirements     145
    Reviewing Future Information Requirements     146
    Reviewing Overall Information Requirements     147
Compiling a Complete List of Fields     148
    The Preliminary Field List     148
    The Calculated Field List     156
    Reviewing Both Lists with Users and Management     156
Summary     162
Review Questions     164
Chapter 7:  Establishing Table Structures     165
Topics Covered in This Chapter     165
Defining the Preliminary Table List     166
    Identifying Implied Subjects     166
    Using the List of Subjects     168
    Using the Mission Objectives     172
Defining the Final Table List     174
    Refining the Table Names     176
    Indicating the Table Types     182
    Composing the Table Descriptions     182
Associating Fields with Each Table     189
Refining the Fields     191
    Improving the Field Names     191
    Using an Ideal Field to Resolve Anomalies     196
    Resolving Multipart Fields     199
    Resolving Multivalued Fields     201
Refining the Table Structures     208
    A Word about Redundant Data and Duplicate Fields     208
    Using an Ideal Table to Refine Table Structures     209
    Establishing Subset Tables     216
Summary     229
Review Questions     231
Chapter 8:  Keys     233
Topics Covered in This Chapter     233
Why Keys Are Important     234
Establishing Keys for Each Table     234
    Candidate Keys     235
    Primary Keys     243
    Alternate Keys     249
    Non-keys     250
Table-Level Integrity     251
Reviewing the Initial Table Structures     251
Summary     259
Review Questions     260
Chapter 9:  Field Specifications     263
Topics Covered in This Chapter     263
Why Field Specifications Are Important     264
Field-Level Integrity     266
Anatomy of a Field Specification     267
    General Elements     267
    Physical Elements     275
    Logical Elements     278
Using Unique, Generic, and Replica Field Specifications     283
Defining Field Specifications for Each Field in the Database     287
Summary     291
Review Questions     292
Chapter 10:  Table Relationships     293
Topics Covered in This Chapter     293
Why Relationships Are Important     294
Types of Relationships     295
    One-to-One Relationships     296
    One-to-Many Relationships     298
    Many-to-Many Relationships     301
    Self-Referencing Relationships     308
Identifying Existing Relationships     312
Establishing Each Relationship     323
    One-to-One and One-to-Many Relationships     323
    The Many-to-Many Relationship     331
    Self-Referencing Relationships     337
    Reviewing the Structure of Each Table     342
Refining All Foreign Keys     343
    Elements of a Foreign Key     343
Establishing Relationship Characteristics     349
    Defining a Deletion Rule for Each Relationship     349
    Identifying the Type of Participation for Each Table     354
    Identifying the Degree of Participation for Each Table     357
    Verifying Table Relationships with Users and Management     360
    A Final Note     360
Relationship-Level Integrity     361
Summary     366
Review Questions     368
Chapter 11:  Business Rules     369
Topics Covered in This Chapter     369
What Are Business Rules?     370
    Types of Business Rules     373
Categories of Business Rules     375
    Field-Specific Business Rules     375
    Relationship-Specific Business Rules     376
Defining and Establishing Business Rules     378
    Working with Users and Management     378
    Defining and Establishing Field-Specific Business Rules     379
    Defining and Establishing Relationship-Specific Business Rules     386
Validation Tables     394
    What Are Validation Tables?     394
    Using Validation Tables to Support Business Rules     395
Reviewing the Business Rule Specifications Sheets     400
Summary     408
Review Questions     409
Chapter 12:  Views     411
Topics Covered in This Chapter     411
What Are Views?     411
Anatomy of a View     413
    Data View     413
    Aggregate View     418
    Validation View     422
Determining and Defining Views     424
    Working with Users and Management     425
    Defining Views     426
    Reviewing the Documentation for Each View     434
Summary     441
Review Questions     442
Chapter 13:  Reviewing Data Integrity     445
Topics Covered in This Chapter     445
Why You Should Review Data Integrity     446
Reviewing and Refining Data Integrity     446
    Table-Level Integrity     447
    Field-Level Integrity     447
    Relationship-Level Integrity     448
    Business Rules     448
    Views     448
Assembling the Database Documentation     449
Done at Last!     451
Summary     452
PART III:  OTHER DATA BASE DESIGN ISSUES     453
Chapter 14:  Bad DesignWhat Not to Do     455
Topics Covered in This Chapter     455
Flat-File Design     456
Spreadsheet Design     457
    Dealing with the Spreadsheet View Mindset     459
Database Design Based on the Database Software     461
A Final Thought     463
Summary     463
Chapter 15:  Bending or Breaking the Rules     465
Topics Covered in This Chapter     465
When May You Bend or Break the Rules?     465
    Designing an Analytical Database     465
    Improving Processing Performance     466
Documenting Your Actions     469
Summary     471
Chapter 16:  In Closing     473

PART IV:  APPENDIXES     475
Appendix A:  Answers to Review Questions     477
Appendix B:  Diagram of the Database Design Process     501
Appendix C:  Design Guidelines     519
Appendix D:  Documentation Forms     529
Appendix E:  Database-Design Diagram Symbols     533
Appendix F:  Sample Designs     535
Appendix G:  On Normalization     541
Appendix H:  Recommended Reading     551
Glossary     553
References     567
Index     569