Le nouveau Cherche et trouve de Little Urban, aussi coloré, déjanté et diablement amusant que le premier (A la recherche de la Carotte bleue), en très très grand format pour le plaisir de tout-petits !!! (Et des plus grands, qui trouvera en premier ?)
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.
Chris Date has a stature in the database industry that's unique. He enjoys a reputation that's second to none for his ability to explain complex technical issues in a clear and understandable fashion. His previous books for O'Reilly include SQL and Relational Theory (2nd edition); Database Design and Relational Theory; and View Updating and Relational Theory. The present book serves as an introduction to those previous ones.