Customer Reviews
find out what a relation really is - By: M. Davies, 08 Oct 2007 
Chris Date has written the only book you need to really understand how databases SHOULD be done building on Ted Codd's relational model. This book will change your perception of all databases & DBMSs especially on the subject of what a relation actually is. Personally I find Date's style of writing very much like the lectures I take (from Hugh Darwen actually so that probably explains it) & contrary to another poster's belief does not basically serve as propeganda on why he is great & all other comentators are wrong but that commentators who don't follow Codd's relational model are HIGHLY flawed.
Unreadable, Leaden, Wearying - By: Dave, 06 Jun 2006 
The author C J Date may know all sorts about databases but he can't write. The prose is so leaden & full of superfluous comments that I gave up. He includes endless bizarre signposts to his intentions, along the lines of "At this pointin the chapter, I would like to pause & make a point on a related topic". Just make the point! More annoyingly, he also uses this book to demonstrate demonstrate his main theme of why he is great & all other database commentators are useless, which leads to yet more unnecessary asides.
There are nuggets of useful informationin here, but a decent editor could reduce this book to a 25 page pamphlet without losing anything much.
If I wasn't so wearied by the effort of wading through the first few chapters I'd send the book back.
Learn Why SQL Is Not A Relational Language - By: David Cross, 29 Dec 2005 
Many years ago when I was a student we were taught database theory. Although Ted Codd's paper "A Relational Model of Data for Large Shared Data Banks" had been published fifteen years earlier, relational databases hadn't yet become the dominant species & we were taught a number of alternatives (does anyone else remember Codasyl?) systems - relational databases & SQL were just the newest option.
Of course, once I left college & started working for a living, it wasn't long before relational databases were the only gamein town. And over the years I've forgotten most of the non-relational theory that I once knew. Or, at least, that's what I thought. Reading this book, I realise that I had forgotten most of the relational theory too.
The relational model is what underpins most of the databases that we usein our day-to-day work. Butin many ways, the databases that we use today have diverged greatly from Codd's original ideas. Many of the features of todays databases would have no placein a purely relational database.
And that is what Chris Date's latest book is all about. He reminds us of what a really relational database would look like & points out where current implementations fall short. In particular, it's clear that Date blames the ubiquity of SQL for most of these problems. SQL, he reminds us, started out as an attempt to put a user-friendly(!) query language on top of the relational model. When that didn't really work out, instead of going back to square one & trying to implement a better relational query language the database vendors instead stuck with SQL & ignored the bits of the relational model which it couldn't support. For most of the examplesin the book, Date gives an SQL query alongside the same query rewrittenin "Tutorial D" a relational query language of his own creation.
The book does contain a useful introduction to the relational model, but I have to say thatin doing so it uses some mathematics that many potential readers might find a bit galling. Personally, I'd be very happy if more database practioners understood the underlying maths to the level required to read this book as that would hopefully mean an increasein the average quality of the database designs that I come across.
Date is at his most interesting when he is talking about the advantages that a "proper" relational database implementation would bring us. As he saysin a recent interview:
"As far as I'm concerned, an object/relational system done right would simply be a relational system done right, nothing more & nothing less."
There are some exciting possibilitiesin a truely relational database, but it would mean the industry admitting that its current implementations are flawed. And I don't see that happening.
If you work with databases & you have any interestin the mathematical theories behind how your database works, then I recommend you read this book. You'll come out with a deeper understanding of your current database system. But, perhaps more importantly, you'll also have a slight sense of disappointment when you realise how good your database could be.
Database in Depth is a Strong Buy - By: , 15 Sep 2005 This book is the second I read on E-R theory & SQL language.
I enjoy reading this book because of:
+ It is very clean & compact. You can understand all, even if you haven't a mathematical background
+ Some of the exposed ideas are new & can change the way you look at the E-R model & theory.
+ Date is a well-known authorin this field, so you can trust a lot what he says
Look also at my review on
