Temporal database systems are systems that provide special support for storing, querying, and updating historical and/or future data. Current DBMSs provide essentially no temporal features at all, but this situation is likely to change soon for a variety of reasons; in fact, temporal databases are virtually certain to become important sooner rather than later, in the commercial world as well as in academia. This book provides an in-depth description of the foundations and principles on which those temporal DBMSs will be built. These foundations and principles are firmly rooted in the relational model of data; thus, they represent an evolutionary step, not a revolutionary one, and they will stand the test of time. This book is arranged in three parts and a set of appendixes:* Preliminaries: Provides a detailed review of the relational model, and an overview of the Tutorial D language.* Laying the Foundations: Explains basic temporal data problems and introduces fundamental constructs and operators for addressing those problems.* Building on the Foundations: Applies the material of the previous part to issues of temporal database design, temporal constraints, temporal query and update, and much more.* Appendixes: Include annotated references and bibliography, implementation considerations, and other topics.Key features:* Describes a truly relational approach to the temporal data problem.* Addresses implementation as well as model issues.* Covers recent research on new database design techniques, a new normal form, new relational operators, new update operators, a new approach to the problem of "granularity," support for "cyclic point types," and other matters.* Includes review questions and exercises in every chapter.* Suitable for both reference and tutorial purposes.
Author(s): C.J. Date, Hugh Darwen, Nikos Lorentzos
Edition: 1
Publisher: Morgan Kaufmann
Year: 2002
Language: English
Pages: 448
Front Cover......Page 1
Temporal Data and the Relational Model......Page 4
Copyright Page......Page 6
Contents......Page 12
Preface......Page 18
Part I: Preliminaries......Page 24
1.1 Introduction......Page 26
1.2 The Running Example......Page 27
1.3 Types......Page 29
1.4 Relation Values......Page 34
1.5 Relation Variables......Page 39
1.6 Integrity Constraints......Page 44
1.7 Relational Operators......Page 46
1.8 The Relational Model......Page 57
Exercises......Page 58
2.3_ Introduction......Page 62
2.2 Scalar Type Definitions......Page 64
2.3 Relational Definitions......Page 65
2.4 Relational Expressions......Page 66
2.5 Relational Assignments......Page 70
2.6 Constraint Definitions......Page 71
Exercises......Page 72
Part II: Laying the Foundations......Page 74
3.1 Introduction......Page 76
3.2 Timestamped Propositions......Page 79
3.3 Valid Time versus Transaction Time......Page 82
3.4 Some Fundamental Questions......Page 84
Exercises......Page 87
4.1 Introduction......Page 88
4.2 "Semitemporalizing" Suppliers and Shipments......Page 90
4.3 Fully Temporalizing Suppliers and Shipments......Page 93
Exercises......Page 98
5.1 Introduction......Page 100
5.2 Applications of Intervals......Page 103
5.3 Point Types and Interval Types......Page 104
5.4 A More Searching Example......Page 108
Exercises......Page 109
6.1 Introduction......Page 112
6.2 Comparison Operators......Page 114
6.3 Other Operators......Page 116
6.4 Sample Queries......Page 118
Exercises......Page 120
7.1 Introduction......Page 122
7.2 Expanded Form......Page 123
7.3 Collapsed Form......Page 124
7.4 Operating on Sets of Intervals......Page 126
7.5 Treating Sets as Unary Relations......Page 128
7.6 Operating on Nullary Relations......Page 130
Exercises......Page 131
8.1 Introduction......Page 132
8.2 Packing Relations......Page 134
8.3 Unpacking Relations......Page 138
8.4 Sample Queries......Page 143
8.5 Packing and Unpacking on No Attributes......Page 146
8.6 Packing and Unpacking on Several Attributes......Page 147
8.7 Further Points......Page 154
Exercises......Page 161
9.1 Introduction......Page 164
9.2 Union, Intersect, and Difference......Page 165
9.3 Restrict and Project......Page 170
9.4 Join......Page 172
9.5 Extend and Summarize......Page 173
9.6 Group and Ungroup......Page 174
9.7 Relational Comparisons......Page 178
9.8 The Underlying Intuition......Page 179
9.9 The Regular Relational Operators Revisited......Page 181
Exercises......Page 182
Part III: Building on the Foundations......Page 184
10.1 Introduction......Page 186
10.2 Current Relvars Only......Page 189
10.3 Historical Relvars Only......Page 192
10.4 Sixth Normal Form......Page 195
10.5 "The Moving Point Now"......Page 200
10.6 Both Current and Historical Relvars......Page 203
10.7 Concluding Remarks......Page 206
Exercises......Page 207
11.1 Introduction......Page 210
11.2 The Redundancy Problem......Page 214
11.3 The Circumlocution Problem......Page 215
11.4 The Contradiction Problem......Page 217
11.6 PACKED ON without WHEN/THEN......Page 219
11.7 WHEN/THEN without PACKED ON......Page 220
11.8 Neither PACKED ON nor WHEN/THEN......Page 227
11.9 Candidate Keys Revisited......Page 230
11.10 PACKED ON Revisited......Page 233
Exercises......Page 234
12.1 Introduction......Page 236
12.2 The Nine Requirements......Page 237
12.3 Current Relvars Only......Page 239
12.4 Historical Relvars Only......Page 243
12.5 Both Current and Historical Relvars......Page 250
12.6 Syntactic Shorthands......Page 262
12.7 Concluding Remarks......Page 266
Exercises......Page 267
13.1 Introduction......Page 268
13.2 Current Relvars Only......Page 270
13.3 Historical Relvars Only......Page 275
13.4 Both Current and Historical Relvars......Page 279
13.5 Virtual Relvars Can Help......Page 283
Exercise......Page 288
14.1 Introduction......Page 290
14.2 Current Relvars Only......Page 291
14.3 Historical Relvars Only (1)......Page 294
14.4 Historical Relvars Only (II)......Page 306
14.5 Both Current and Historical Relvars......Page 309
14.6 Virtual Relvars Can Help......Page 315
Exercises......Page 318
15.1 Introduction......Page 320
15.2 A Closer Look......Page 322
15.3 The Database and the Log......Page 325
15.4 Terminology......Page 328
15.5 Logged-Time Relvars......Page 331
15.6 Queries Involving Logged-Time Relvars......Page 334
Exercises......Page 335
16.1 Introduction......Page 336
16.2 Type Inheritance......Page 338
16.3 Point Types Revisited......Page 344
16.4 Further Examples......Page 347
16.5 Granularity Revisited......Page 354
16.6 Interval Types Revisited......Page 358
16.7 Cyclic Point Types......Page 360
16.8 Continuous Point Types......Page 367
Exercises......Page 370
APPENDIXES......Page 372
Appendix A. IMPLEMENTATION CONSIDERATIONS......Page 374
Appendix B. GENERALIZING THE EXPAND AND COLLAPSE OPERATORS......Page 406
Appendix C. REFERENCES AND BIBLIOGRAPHY......Page 414
INDEX......Page 434
ABOUT THE AUTHORS......Page 444
