Chris Date, one of the founders of the relational model, has updated and expanded his relational database dictionary to include more than 900 terms.

No matter what DBMS you are using—Oracle, DB2, SQL Server, MySQL, PostgreSQL—misunderstandings can always arise over the precise meanings of terms, misunderstandings that can have a serious effect on the success of your database projects. For example, here are some common database terms: attribute, BCNF, consistency, denormalization, predicate, repeating group, join dependency. Do you know what they all mean? Are you sure? The New Relational Database Dictionary defines all of these terms and many, many more. Carefully reviewed for clarity, accuracy, and completeness, this book is an authoritative and comprehensive resource for database professionals, with over 1700 entries (many with examples) dealing with issues and concepts arising from the relational model of data. DBAs, database designers, DBMS implementers, application developers, and database professors and students can find the information they need on a daily basis, information that isn’t readily available anywhere else.

This book provides a single source where designers, programmers, students, and DBAs using Oracle, SQL Server, DB2, MySQL, PostgreSQL, and other relational database systems can find precise definitions.

Time and Relational Theory provides an in-depth description of temporal database systems, which provide special facilities for storing, querying, and updating historical and future data. Traditionally, database management systems provide little or no special support for temporal data at all. This situation is changing because: - Cheap storage enables retention of large volumes of historical data in data warehouses - Users are now faced with temporal data problems, and need solutions - Temporal features have recently been incorporated into the SQL standard, and vendors have begun to add temporal support to their DBMS products Based on the groundbreaking text Temporal Data & the Relational Model (Morgan Kaufmann, 2002) and new research led by the authors, Time and Relational Theory is the only book to offer a complete overview of the functionality of a temporal DBMS. Expert authors Nikos Lorentzos, Hugh Darwen, and Chris Date describe an approach to temporal database management that is firmly rooted in classical relational theory and will stand the test of time. This book covers the SQL:2011 temporal extensions in depth and identifies and discusses the temporal functionality still missing from SQL. - Understand how the relational model provides an ideal basis for taming the complexities of temporal databases - Learn how to analyze and evaluate commercial temporal products with this timely and important information - Be able to use sound principles in designing and using temporal databases - Understand the temporal support recently added to SQL with coverage of the new SQL features in this unique, accurate, and authoritative reference - Appreciate the benefits of a truly relational approach to the problem with this clear, user friendly presentation

Understanding SQL's underlying theory is the best way to guarantee that your SQL code is correct and your database schema is robust and maintainable. On the other hand, if you're not well versed in the theory, you can fall into several traps. In SQL and Relational Theory, author C.J. Date demonstrates how you can apply relational theory directly to your use of SQL. With numerous examples and clear explanations of the reasoning behind them, you'll learn how to deal with common SQL dilemmas, such as: Should database access granted be through views instead of base tables? Nulls in your database are causing you to get wrong answers. Why? What can you do about it? Could you write an SQL query to find employees who have never been in the same department for more than six months at a time? SQL supports "quantified comparisons," but they're better avoided. Why? How do you avoid them? Constraints are crucially important, but most SQL products don't support them properly. What can you do to resolve this situation? Database theory and practice have evolved since Edgar Codd originally defined the relational model back in 1969. Independent of any SQL products, SQL and Relational Theory draws on decades of research to present the most up-to-date treatment of the material available anywhere. Anyone with a modest to advanced background in SQL will benefit from the many insights in this book.

A note from the authors: Dear Reader: "Database is boring." That sentiment is heard all too widely these days. But it's so wrong! The database field is full of important problems still to be solved and interesting issues still to be examined - and some of those problems and issues are explored in this book. Between us, we have nearly 80 years experience in this field, and we're still actively researching, exploring, and learning, as well as helping others do the same. The present book is the latest in a series devoted to these goals; using "The Third Manifesto" (a detailed proposal for the future of database technology) as a foundation, it reports on some of our most recent investigations in this field. Among many other things, it includes the most recent version of "The Third Manifesto" itself; specifications for a conforming language called Tutorial D; and a detailed proposal for a model of type inheritance. Other significant features include: - Extending the foreign key concept - Simplifying queries using image relations - Closer looks at logic and relational algebra - Suggested approaches to "missing information" - Responses to certain "Manifesto" criticisms - Clarifying aspects of normalization The tone of the book overall is naturally somewhat serious, but there are moments of light relief as well. We hope you enjoy it. C.J. Date and Hugh Darwen

Because databases often stay in production for decades, careful design is critical to making the database serve the needs of your users over years, and to avoid subtle errors or performance problems. In this book, C.J. Date, a leading exponent of relational databases, lays out the principles of good database design.