Views are virtual tables. That means they should be updatable, just as "real" or base tables are. In fact, view updatability isn’t just desirable, it’s crucial, for practical reasons as well as theoretical ones. But view updating has always been a controversial topic. Ever since the relational model first appeared, there has been widespread skepticism as to whether (in general) view updating is even possible. In stark contrast to this conventional wisdom, this book shows how views, just like base tables, can always be updated (so long as the updates don’t violate any integrity constraints). More generally, it shows how updating always ought to work, regardless of whether the target is a base table or a view. The proposed scheme is 100% consistent with the relational model, but rather different from the way updating works in SQL products today. This book can: Help database products improve in the future Help with a "roll your own" implementation, absent such product improvements Make you aware of the crucial role of predicates and constraints Show you how relational products are really supposed to behave Anyone with a professional interest in the relational model, relational technology, or database systems in general can benefit from this book.
This book can: Help database products improve in the future Help with a "roll your own" implementation, absent such product improvements Make you aware of the crucial role of predicates and constraints Show you how relational products are ...
In stark contrast to this conventional wisdom, this book shows how views, just like base tables, can always be updated (so long as the updates don't violate any integrity constraints).
But are those products truly relational? Sadly, the answer is no. This book shows you what a real relational product would be like, and how and why it would be so much better than what’s currently available.
Jim Melton and Alan R. Simon: SQL:1999─Understanding Relational Components; Jim Melton: Advanced SQL:1999─Understanding Object-Relational and Other Advanced Features. San Francisco, Calif.: Morgan Kaufmann (2002 and 2003, ...
Jim Melton and Alan R. Simon: SQL:1999—Understanding Relational Components; Jim Melton: Advanced SQL:1999—Understanding Object-Relational and Other Advanced Features. San Francisco, Calif.: Morgan Kaufmann (2002 and 2003, respectively).
This book draws on decades of experience to present the most up to date treatment of the material possible. Anyone with a professional interest in databases can benefit from the insights it contains. The book is product independent.
In this insightful book, author C.J. Date explains relational theory in depth, and demonstrates through numerous examples and exercises how you can apply it directly to your use of SQL.
And yet few people, even in the professional database community, are truly familiar with those papers. This book is an attempt to remedy this sorry state of affairs.
This concise guide sheds light on the principles behind the relational model, which underlies all database products in wide use today.
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?