Managing Time in Databases

Tom Johnston 지음

elsevier 2010년 08월 19일 출간

작품소개

책소개

This book presents a comprehensive view of how to manage a temporal database. Temporal data management refers to an integrated method of managing data about the past, present, and future of the objects and events of interest to the user. That is, managing non-current data in relational databases in such a way that past data can be seamlessly accessed together with current data with result sets containing both current and non-current data that can be retrieved with queries simple enough for a business user to write and with result set response times very close to those for result sets containing current data only. For example, let's say that from July through August of last year we had on our database a row stating that the unit cost of a product was $25.50 during the first quarter of that year. But in September, we realized that we had made a mistake and that the unit cost was actually $23.50. End users need the ability to issue a query which can tell them both what the unit cost really was in the first quarter of last year and also a query which can tell them what they said the first-quarter unit cost was last July. The practical and comprehensive nature of this material is demonstrated in each chapter by a mixture of diagrams and text typical for a book about data architecture and data models. The chapters dealing specifically with managing temporal and bi-temporal data will rely heavily on an example-driven approach, each example presenting specific real-world scenarios. Each scenario is structured around (a) a before-image of a sample table or tables; (b) a bi-temporal timeline graphic; (c) a specific bi-temporal transaction; and (d) one or more snapshots of the sample table or tables, showing the results of applying each transaction. (Bi-temporal relational data is temporarily delimited into two dimensions, i.e., valid time and transaction time.) For example, a hedge fund company needs to bi-temporally manage a lot of their econo

목차

Part 1. Introduction.Chapter 1. Historical ContextualizationChapter 2. A Taxonomy of Methods of Managing Time in Databases.Chapter 3. Temporal Data Management in Enterprise Data Architecture.Chapter 4. The Objectives and Origins of Asserted Versioning.Chapter 5. Basic Concepts of Asserted Versioning.Part 2. Current Practice in Temporal Data Management.Chapter 6. Baseline: Updates in Place.Chapter 7. Standard Practice: Adding a Date to a Primary Key.Chapter 8. Best Practice: Using Effective Date Pairs.Part 3. Asserted Versions: a New Approach to Bi-Temporal Data Management.Chapter 9. Objects, Episodes, Versions and Assertions.Chapter 10.The Mechanics of Maintaining Versioned Objects.Chapter 11. The Semantics of Maintaining Versioned Objects.Chapter 12. Querying Versioned Objects.Part 4. Introducing Versioned Objects into the Enterprise.Chapter 13. A Business-Driven Approach to Bi-Temporality Chapter 14. Surrogate Keys.Chapter 15. Versioned Objects, Warehouse Snapshots and Versioned DimensionsChapter 16. Maximizing Performance for Bi-Temporal Tables.Part 5. Related Matters.Chapter 17. Temporal Dimensions and Codd's Information Principle.Chapter 18. Deferred Transactions and Future States.Chapter 19. Sandboxes and Release Management.Chapter 20. The Problem of Identifying Recurring Objects.Chapter 21. Other Kinds of Asserted Versions.Part 6. The Asserted Versioning Prototype.Chapter 22. Specifying Asserted Version Tables.Chapter 23. Generating Asserted Version Tables From ERwin Macros.Chapter 24. Using the Prototype.

출판사 서평

"You cannot escape temporal data. You need to get over it, sit down and read what Tom and Randy are telling you in this book. " Joe Celko, Independent Consultant & Columnist for Intelligent Enterprise, USA "The authors present an original and comprehensive conceptual approach called Asserted Versioning, which includes support for bi-temporality and is a significant advance in the theory and practice of managing time-varying data." Richard Snodgrass, Professor of Computer Science at the University of Arizona

작가정보

저자(글) Tom Johnston