Data Modeling Essentials, Third Edition (Morgan Kaufmann Series in Data Management Systems)

Cover......Page 1
Contents......Page 8
Preface......Page 24
Part I. The Basics......Page 30
1.2 A Data-Centered Perspective......Page 32
1.3 A Simple Example......Page 33
1.4 Design, Choice, and Creativity......Page 35
1.5 Why Is the Data Model Important?......Page 37
1.6 What Makes a Good Data Model?......Page 39
1.7 Performance......Page 44
1.8 Database Design Stages and Deliverables......Page 45
1.9 Where Do Data Models Fit In?......Page 49
1.10 Who Should Be Involved in......Page 52
1.11 Is Data Modeling Still Relevant?......Page 53
1.12 Alternative Approaches to Data Modeling......Page 58
1.13 Terminology......Page 59
1.14 Where to from Here?—An Overview......Page 60
1.15 Summary......Page 61
2.1 Introduction......Page 62
2.2 An Informal Example of Normalization......Page 63
2.3 Relational Notation......Page 65
2.4 A More Complex Example......Page 66
2.5 Determining Columns......Page 69
2.6 Repeating Groups and First Normal Form......Page 72
2.7 Second and Third Normal Forms......Page 76
2.8 Definitions and a Few Refinements......Page 82
2.9 Choice, Creativity, and Normalization......Page 89
2.10 Terminology......Page 91
2.11 Summary......Page 92
3.2 A Diagrammatic Representation......Page 94
3.3 The Top-Down Approach:......Page 101
3.4 Entity Classes......Page 105
3.5 Relationships......Page 111
3.6 Attributes......Page 133
3.7 Myths and Folklore......Page 134
3.8 Creativity and E-R Modeling......Page 135
3.9 Summary......Page 138
4.2 Different Levels of Generalization......Page 140
4.3 Rules versus Stability......Page 142
4.4 Using Subtypes and Supertypes......Page 144
4.5 Subtypes and Supertypes as Entity Classes......Page 145
4.6 Diagramming Conventions......Page 146
4.8 Attributes of Supertypes and Subtypes......Page 148
4.9 Nonoverlapping and Exhaustive......Page 149
4.10 Overlapping Subtypes and Roles......Page 152
4.11 Hierarchy of Subtypes......Page 156
4.12 Benefits of Using Subtypes and Supertypes......Page 157
4.13 When Do We Stop Supertyping......Page 163
4.14 Generalization of Relationships......Page 167
4.15 Theoretical Background......Page 171
4.16 Summary......Page 172
5.1 Introduction......Page 174
5.2 Attribute Definition......Page 175
5.3 Attribute Disaggregation: One......Page 176
5.4 Types of Attributes......Page 181
5.5 Attribute Names......Page 195
5.6 Attribute Generalization......Page 200
5.7 Summary......Page 209
6.1 Basic Requirements and Trade-Offs......Page 212
6.2 Basic Technical Criteria......Page 214
6.3 Surrogate Keys......Page 220
6.4 Structured Keys......Page 223
6.5 Multiple Candidate Keys......Page 230
6.6 Guidelines for Choosing Keys......Page 231
6.7 Partially-Null Keys......Page 233
6.8 Summary......Page 235
7.1 Introduction......Page 236
7.2 Extensions to the Basic E-R Approach......Page 238
7.3 The Chen E-R Approach......Page 245
7.4 Using UML Object Class Diagrams......Page 249
7.5 Object Role Modeling......Page 256
7.6 Summary......Page 257
Part II. Putting It Together......Page 258
8.1 Data Modeling in the Real World......Page 260
8.2 Key Issues in Project Organization......Page 262
8.3 Roles and Responsibilities......Page 267
8.4 Partitioning Large Projects......Page 269
8.5 Maintaining the Model......Page 271
8.6 Packaging It Up......Page 277
8.7 Summary......Page 278
9.1 Purpose of the Requirements Phase......Page 280
9.2 The Business Case......Page 282
9.3 Interviews and Workshops......Page 283
9.4 Riding the Trucks......Page 287
9.5 Existing Systems and Reverse......Page 288
9.7 Object Class Hierarchies......Page 290
9.8 Summary......Page 299
10.1 Designing Real Models......Page 302
10.2 Learning from Designers in Other......Page 304
10.3 Starting the Modeling......Page 305
10.4 Patterns and Generic Models......Page 306
10.5 Bottom-Up Modeling......Page 314
10.7 When the Problem Is Too Complex......Page 317
10.8 Hierarchies, Networks, and Chains......Page 319
10.9 One-to-One Relationships......Page 324
10.10 Developing Entity Class Definitions......Page 329
10.11 Handling Exceptions......Page 330
10.12 The Right Attitude......Page 331
10.13 Evaluating the Model......Page 334
10.14 Direct Review of Data Model Diagrams......Page 335
10.16 Testing the Model with Sample Data......Page 337
10.18 The Assertions Approach......Page 338
10.19 Summary......Page 348
11.1 Introduction......Page 350
11.2 Overview of the Transformations......Page 351
11.3 Table Specification......Page 354
11.4 Basic Column Definition......Page 363
11.5 Primary Key Specification......Page 370
11.6 Foreign Key Specification......Page 371
11.7 Table and Column Names......Page 383
11.8 Logical Data Model Notations......Page 384
11.9 Summary......Page 386
12.1 Introduction......Page 388
12.2 Inputs to Database Design......Page 390
12.3 Options Available to the Database Designer......Page 391
12.4 Design Decisions Which Do Not Affect......Page 392
12.5 Crafting Queries to Run Faster......Page 401
12.6 Logical Schema Decisions......Page 403
12.7 Views......Page 413
12.8 Summary......Page 415
Part III. Advanced Topics......Page 418
13.1 Introduction......Page 420
13.2 Introduction to the Higher Normal Forms......Page 421
13.3 Boyce-Codd Normal Form......Page 423
13.4 Fourth Normal Form (4NF) and......Page 427
13.5 Beyond 5NF: Splitting Tables Based on......Page 436
13.6 Other Normalization Issues......Page 437
13.7 Advanced Normalization in Perspective......Page 444
13.8 Summary......Page 445
14.1 Introduction......Page 446
14.2 Types of Business Rules......Page 447
14.3 Discovery and Verification of Business Rules......Page 449
14.4 Documentation of Business Rules......Page 451
14.5 Implementing Business Rules......Page 456
14.6 Rules on Recursive Relationships......Page 475
14.7 Summary......Page 479
15.1 The Problem......Page 480
15.3 Audit Trails and Snapshots......Page 481
15.4 Sequences and Versions......Page 491
15.6 Archiving......Page 492
15.7 Modeling Time-Dependent Relationships......Page 493
15.9 Temporal Business Rules......Page 498
15.11 Putting It into Practice......Page 502
15.12 Summary......Page 503
16.1 Introduction......Page 504
16.2 Characteristics of Data Warehouses......Page 507
16.3 Quality Criteria for Warehouse......Page 509
16.4 The Basic Design Principle......Page 512
16.5 Modeling for the Data Warehouse......Page 513
16.6 Modeling for the Data Mart......Page 517
16.7 Summary......Page 525
17.1 Introduction......Page 528
17.2 Data Management......Page 529
17.3 Classification of Existing Data......Page 532
17.4 A Target for Planning......Page 533
17.5 A Context for Specifying New Databases......Page 535
17.7 Input to Business Planning......Page 537
17.8 Specification of an Enterprise Database......Page 538
17.9 Characteristics of Enterprise Data Models......Page 540
17.10 Developing an Enterprise Data Model......Page 541
17.11 Choice, Creativity, and Enterprise......Page 545
17.12 Summary......Page 546
Further Reading......Page 548
Index......Page 554