Foreword p. xxi
Preface p. xxiii
Introduction p. 1
Logical Data Structures and Physical Data Storage p. 4
Summary p. 16
Exercises p. 17
Good Habits p. 19
Employ the Users' Language and Vocabulary p. 19
Be Rigorous p. 21
Don't Rely on the Opinion of a Single Expert; Ask Several p. 22
Ask First About Data, Not About Processing p. 23
Master the Shapes of Data p. 25
Use a Notation That Helps You Realize These Good Habits p. 26
Summary p. 26
Exercises p. 27
Reading an LDS with Sentences p. 29
Sentences About What Users Can Remember p. 29
Sentences About Differentiating Things from Each Other p. 37
Sentences You Should Not Say p. 41
Some Complete Examples p. 42
Summary p. 43
Exercises p. 44
Vocabulary of LDS p. 47
Vocabulary Overview p. 48
A Bit More About Entities, Attributes, and Relationships p. 55
LDS Reading Rules Revisited p. 57
Responsibility for Speaking Well p. 59
Summary (and a Chance to Check Your Progress) p. 59
Exercises p. 61
Visualizing Allowed and Disallowed Instances p. 65
Show the Data and Say Something About It p. 66
Plan Your Notes by Considering Elemental Parts of the LDS p. 67
As You Visualize Data, Don't Lose Sight of the Goal p. 72
Exercises p. 73
A Conversation with Users About Creatures and Skills p. 75
Summary p. 84
Exercises p. 85
Story Interlude p. 86
Introduction to Mastering Shapes p. 91
Definition of Shape p. 91
Mastering Shapes p. 93
Reading a Shape Aloud in Several Ways p. 94
Visualizing Sample Data in Several Formats p. 95
Discussing and Illustrating Noteworthy Disallowed Data p. 96
Finding and Focusing on Shapes Within a Large LDS p. 97
Recognizing the Differences Between Shapes That Are Similar but Not Identical p. 99
Recognizing the Similarity Between Seemingly Dissimilar Shapes p. 101
Distinguishing Between Legitimate Shapes and Syntactically Invalid LDS Fragments p. 102
Knowing How Shapes Are Likely to Evolve p. 103
Asking Questions That Help Users Choose Between Two Similar Shapes p. 103
Knowing When to Ask Questions of Users p. 104
Knowing When and How to Modify the LDS to Make a Shape Evolve p. 104
Understanding the Relative Frequency of the Various Shapes p. 105
Referring to each Fundamental Shape by Its Name p. 105
Exercises p. 105
One-Entity, No-Relationship Shapes p. 107
Shape: Common Independent Entity p. 108
Shape: Lonely-Attribute Independent Entity p. 109
Shape: Aggregate Independent Entity p. 110
Shape: Dependent Entity p. 112
Shape: Intersection Entity p. 112
Shape: Subordinate Entity p. 113
Shape: One-Many Collection Entity p. 114
Shape: Many-Many Collection Entity p. 115
Unnamed Possibilities p. 116
Exercises p. 116
One-Attribute Shapes p. 117
Scale p. 117
Shape: Nominal-Scale Attributes p. 118
Shape: Numeric-Scale Attributes p. 118
Shape: Ordinal-Scale Attributes p. 119
Shape: Boolean-Scale Attributes p. 119
Scale and Datatype p. 119
Scale and Attribute Names p. 120
Fine Distinctions of Scale p. 120
Scale and Abstract Datatypes p. 121
Summary of How Scale Restricts an Attribute p. 121
Exercises p. 122
Two-Entity Shapes p. 123
Two Entities, One Relationship p. 123
One-Many Shapes p. 124
One-One Shapes p. 125
Many-Many Shapes p. 129
Two Entities, Two Relationships p. 130
One-One and One-Many Relationship p. 132
Two One-Many Relationships p. 133
Shape: Two Entities, n Relationships p. 136
Exercises p. 138
Shapes with More Than Two Entities p. 139
Shape: Chicken Feet In p. 139
Shape: Chicken Feet Out p. 141
Shape: Chicken Feet Across p. 143
Shape: Subordinates Out p. 145
Shape: Subordinates Across p. 145
Shape: Multiple Plain To-be Relationships p. 146
Shape: Multiple To-be Relationships p. 147
Shape: Multiple Short Paths p. 147
Exercises p. 149
Shapes with Reflexive Relationships p. 151
Shape: One-One Reflexive Relationship p. 151
Sequence Data and Cyclic Sequence Data p. 153
Ordered Pairs p. 155
Shape: One-Many Reflexive Relationship p. 156
Shape: Many-Many Reflexive Relationship p. 158
Exercises p. 159
Story Interlude p. 160
LDS Syntax Rules p. 165
Within Any LDS, Each Entity, Attribute, Relationship, and Link Has an Official Name That Is Unique p. 165
No Reflexive Relationship Is a To-be Relationship p. 167
Between Any Pair of Entities, There Is at Most One To-be Relationship p. 167
Each Entity Has at Least One Identifier p. 167
An Entity Can Have Several Identifiers p. 167
No Identifier Can Be a Strict Subset of Another p. 168
The LDS Cannot Contain Any Cycles of Identification Dependency p. 168
No Link of a Reflexive Relationship Can Contribute to an Identifier p. 170
Both Links of a Relationship Cannot Contribute to Identifiers p. 170
A Single-Descriptor Identifier Cannot Include the Degree-One Link of a One-Many Relationship p. 170
A Multiple-Descriptor Identifier Cannot Include a Link of a One-One Relationship p. 171
A Multiple-Descriptor Identifier Cannot Include the Degree-Many Link of a One-Many Relationship p. 172
A Relationship Has Either Two Labels or Zero Labels p. 173
All One-One Relationships Have Labels p. 173
All Reflexive Relationships Have Labels p. 173
Between Any Pair of Entities, There Is at Most One Unlabeled Relationship p. 173
Valid Relationships p. 174
Exercises p. 176
Getting the Names Right p. 177
Entity Names p. 177
Working with Users to Get the Entity Names Right p. 184
Naming Attributes p. 190
Naming Relationships and Links p. 191
Exercises p. 191
Official Names p. 193
Official Names Can Be Awkward p. 193
A Few Notes About Official Names and To-be Relationships p. 198
Exercises p. 199
Labeling Links p. 201
Exercises p. 207
Documenting an LDS p. 209
The Audience p. 210
Front Matter p. 210
Entity Documentation p. 211
Attribute Documentation p. 211
Link Documentation p. 212
Relationship Documentation p. 212
Fragment Documentation p. 212
Constraint Documentation p. 213
Issues List p. 213
Supplemental Material for Secondary Audiences p. 214
Exercises p. 215
Story Interlude p. 216
Script for Controlled Evolution: The Flow p. 219
Script for The Flow p. 219
Discussing a Not-to-be Relationship p. 222
Flow Stage: Not-to-be Relationship p. 225
Flow Investigation: Seek a Chicken Foot p. 225
Flow Investigation: Seek a One-Many Relationship p. 227
Flow Investigation: Seek a Many-Many Relationship p. 228
Flow Stage: One-One, Not-to-be Relationship p. 229
Flow Stage: One-Many Relationship p. 230
Flow Stages: Initial Many-Many Relationship and New Intersection Entity p. 230
Developing a Chicken-Feet-In Shape p. 233
Flow Investigation: Seek Descriptors for Intersection Entity p. 235
Flow Investigation: Seek Tiebreaker p. 235
Flow Investigation: Consider Overidentification p. 236
Flow Investigation: Seek Independent Entity p. 236
Discussing a To-be Relationship p. 237
Flow Investigation: Consider Synonymy p. 237
Flow Investigation: Consider Subordination p. 237
Continuing the Discussion p. 238
Flow Continuation: Seek Other Relationships p. 238
Flow Continuation: Seek Further Evolution for a One-Many Relationship p. 238
Flow Continuation: Seek Further Evolution for the Chicken-Feet-Across Shape p. 239
Flow Continuation: Seek Further Evolution for the Chicken-Feet-In Shape p. 240
Exercises p. 246
Local, Anytime Steps of Controlled Evolution p. 247
Discovering Entities p. 248
Fixing Identifiers p. 249
Seeking Descriptors p. 252
Promoting Attributes p. 254
Relocating Misplaced Descriptors p. 257
Exercises p. 266
Global, Anytime Steps of Controlled Evolution p. 269
Redrawing the Diagram p. 269
Altering the Overall Style of an LDS p. 270
Changing the Level of Abstraction p. 271
Exercises p. 276
Conversations About Dairy Farming p. 277
Meeting with Users from the General Offices p. 277
Meeting with Veterinary Epidemiologists p. 281
Meeting with Economic Analysts p. 284
Exercises p. 290
Story Interlude p. 292
Constraints p. 295
Constraint Definition Requires a Stabilized Data Model p. 295
Many Candidate Constraints Turn Out to Be False p. 296
Many Constraints Subject a Data Model to Premature Obsolescence p. 296
Worthy Constraints p. 297
Constraints and Shifting the Burden p. 298
Summary and Final Thoughts p. 299
Exercises p. 300
LDS for LDS p. 301
The Meta-LDS p. 301
Discussion p. 304
Summary p. 311
Exercises p. 312
Decisions: Designing a Data-Modeling Notation p. 313
Overall Decisions p. 315
Decisions About Entities p. 317
Decisions About Identifiers p. 319
Decisions About Attributes p. 320
Decisions About Relationships p. 323
Decisions About Links p. 326
Decisions About Descriptors p. 327
Decisions About Constraints p. 328
Summary and Final Thoughts p. 332
Exercises p. 332
LDS and the Relational Model p. 333
Relational Databases p. 334
Mapping an LDS to a Relational Schema p. 335
LDS and Normal Forms p. 339
Summary p. 343
Exercises p. 344
Cookbook: Recipes for Data Modelers p. 345
Set Recipes p. 346
Graph Recipes p. 347
Matrix Recipes p. 349
Taxonomy and Near-Taxonomy Recipes p. 351
Exercises p. 353
Story Interlude p. 354
Exercises for Mastery p. 359
Index p. 367