James F. Allen. “Maintaining Knowledge About Temporal Intervals.” Communications of the ACM (November 1983), 26(11), 832–843. This article defined a set of 13 positional relationships between two time periods along a common timeline. These relationships are a partitioning of all possible positional temporal relationships. They are mutually exclusive, and there are no others.

B. A. Devlin and P. T. Murphy. “An Architecture for a Business and Information System.” IBM Systems Journal (1988), 27(1). To the best of our knowledge, this article is the origin of data warehousing in just as incontrovertible a sense as Dr. E. F. Codd's early articles were the origins of relational theory.

William Inmon. Building the Data Warehouse, 2nd ed. (John Wiley, 1996). (The first edition was apparently published in 1991, but we can find no reliable references to it.) With this book, Inmon began his work of introducing the concepts of data warehousing to the rest of the IT profession, in the process extending the concept into several iterations of his own data warehousing architecture.

Ralph Kimball. The Data Warehouse Toolkit: Practical Techniques for Building Dimensional Data Warehouses (John Wiley, 1996). This book, and later “data warehouse toolkit” books, introduced and developed Kimball's event-centric approach to managing historical data. Concepts such as dimensional data marts, the fact vs. dimension distinction, and star schemas and snowflake schemas are all grounded in Kimball's work, as is the entire range of OLAP and business intelligence software.

R. T. Snodgrass. Developing Time-Oriented Database Applications in SQL (Morgan-Kaufmann, 2000). Both this book and our own are concerned with explaining how to support bi-temporal data management using current DBMSs and current SQL.

This book is an invaluable source of SQL code fragments that illustrate the complexity of managing bi-temporal data and, in particular, that illustrate how to write temporal entity integrity and temporal referential integrity checks.

This book is available in PDF form, at no cost, at Dr. Snodgrass's website: http://www.cs.arizona.edu/people/rts/publications.html.

Tom Johnston. “Primary Key Reengineering Projects: The Problem.” Information Management Magazine (February 2000). http://www.information-management.com/issues/20000201/1866-1.html

Tom Johnston. “Primary Key Reengineering Projects: The Solution.” Information Management Magazine (March 2000). http://www.information-management.com/issues/20000301/2004-1.html

These two articles, by one of the authors, explain why he believes that all relational tables should use surrogate keys rather than business keys. Additional material on this topic can be found at his website, MindfulData.com. For anyone contemplating the idea of an Asserted Versioning Framework of their own, in which they use business keys as primary keys instead of Asserted Versioning's object identifiers (oids), we recommend that you read these articles first.

Tom Johnston. “Unobvious Redundancies in Relational Data Models, Part 1.” InfoManagement Direct (September 2001). http://www.information-management.com/infodirect/20010914/4007-1.html

Tom Johnston. “Unobvious Redundancies in Relational Data Models, Part 2.” InfoManagement Direct (September 2001). http://www.information-management.com/infodirect/20010921/4017-1.html

Tom Johnston. “Unobvious Redundancies in Relational Data Models, Part 3.” InfoManagement Direct (September 2001). http://www.information-management.com/infodirect/20010928/4037-1.html

Tom Johnston. “Unobvious Redundancies in Relational Data Models, Part 4.” InfoManagement Direct (October 2001). http://www.information-management.com/infodirect/20011005/4103-1.html

Tom Johnston. “Unobvious Redundancies in Relational Data Models, Part 5.” InfoManagement Direct (October 2001). http://www.information-management.com/infodirect/20011012/4132-1.html

These five articles, by one of the authors, show how fully normalized relational data models may still contain data redundancies. The issue of redundancies that do not violate normal forms was raised in Chapter 15, where we discussed our reasons for repeating the effective begin date of the initial version of every episode on all the non-initial versions of those same episodes.

C. J. Date, Hugh Darwen, Nikos Lorentzos. Temporal Data and the Relational Model (Morgan-Kaufmann, 2002). While the main focus of our book and the book by Dr. Snodgrass is row-level bi-temporality, the main focus of Date, Darwen, and Lorentzos's book is column-level versioning. While the main focus of our book and Snodgrass's is on implementing temporal data management with today's DBMSs and today's SQL, the main focus of their book is on describing language extensions that contain new operators for manipulating versioned data.

This series of some two dozen articles by the authors, succeeded by a bi-monthly column of the same name and about the same number of installments, began in the May 2007 issue of DM Review magazine, now Information Management. The entire set, amounting to some 50 articles and columns combined, ended in June of 2009. Although we had designed and built bi-temporal databases prior to writing these articles, our ideas evolved a great deal in the process of writing them. For example, although we emphasized the importance of maintenance encapsulation in the first article, we did not distinguish between temporal and physical transactions. All in all, we do not believe that these articles can usefully be consulted to gain additional insight into the topics discussed in this book. Although we intended them as instructions to other modelers and developers on how to implement bi-temporal data in today's DBMSs, we now look back on them as an on-line diary of our evolving ideas on the subject.

Oracle Database 11g Workspace Manager Overview. An Oracle White Paper (September 2009). http://www.oracle.com/technology/products/database/workspace_manager/pdf/twp_AppDev_Workspace_Manager_11g.pdf

A discussion of the Oracle 11g Workspace Manager, and in particular its key role in implementing Oracle's support for bi-temporal data management. On our website, we compare and contrast this implementation of a framework for bi-temporal data management with Asserted Versioning.

The best Internet source for an introduction to philosophical concepts, including those used in this book, is the Stanford Encyclopedia of Philosophy, at http://plato.stanford.edu/. Unfortunately, while each entry is individually excellent, the choice of which concepts to include seems somewhat idiosyncratic. For example, there is no general entry for ontology. Nonetheless, we recommend the following entries there, as relevant to the concepts used in this book: assertion, change, epistemology, facts, Arthur Prior, propositional attitude reports, speech acts, temporal logic, temporal parts.

There are, of course, numerous other excellent introductions to philosophical concepts available on the Web. The problem is that there are also numerous other very poor ones, too! Philosophy is a topic that seems to lend itself to this kind of variety. We would recommend to those interested, that as a general rule, sources at dot-edu domains can be presumed reliable, while sources at other domains should be treated with caution.

In this bibliography, we include no direct references to the computer science literature on temporal data management because most of that literature will not be available to many of our readers. For those who wish to access this material, we recommend getting a membership in the ACM and subscribing to the ACM Digital Library. Downloadable PDF copies of hundreds and probably thousands of articles on the management of temporal data are available from that source.

Another invaluable—and free!—source of information on temporal databases, with many links to other resources, can be found on Dr. Snodgrass's website, specifically at http://www.cs.arizona.edu/people/rts/publications.html.