find out what a relation really is, 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 and 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) and contrary to another poster's belief does not basically serve as propeganda on why he is great and all other comentators are wrong but that commentators who don't follow Codd's relational model are HIGHLY flawed.

Unreadable, Leaden, Wearying, 06 Jun 2006
The author C J Date may know all sorts about databases but he can't write. The prose is so leaden and full of superfluous comments that I gave up. He includes endless bizarre signposts to his intentions, along the lines of "At this point in the chapter, I would like to pause and 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 and all other database commentators are useless, which leads to yet more unnecessary asides.

There are nuggets of useful information in 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, 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 and we were taught a number of alternatives (does anyone else remember Codasyl?) systems - relational databases and SQL were just the newest option.

Of course, once I left college and started working for a living, it wasn't long before relational databases were the only game in 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 use in our day-to-day work. But in 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 place in 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 and 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 and trying to implement a better relational query language the database vendors instead stuck with SQL and ignored the bits of the relational model which it couldn't support. For most of the examples in the book, Date gives an SQL query alongside the same query rewritten in "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 that in 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 increase in 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 says in 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 and nothing less."

There are some exciting possibilities in 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 and you have any interest in 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, 15 Sep 2005
This book is the second I read on E-R theory and SQL language.
I enjoy reading this book because of:
+ It is very clean and compact. You can understand all, even if you haven't a mathematical background
+ Some of the exposed ideas are new and can change the way you look at the E-R model and theory.
+ Date is a well-known author in this field, so you can trust a lot what he says

Look also at my review on

find out what a relation really is, 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 and 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) and contrary to another poster's belief does not basically serve as propeganda on why he is great and all other comentators are wrong but that commentators who don't follow Codd's relational model are HIGHLY flawed.

Unreadable, Leaden, Wearying, 06 Jun 2006
The author C J Date may know all sorts about databases but he can't write. The prose is so leaden and full of superfluous comments that I gave up. He includes endless bizarre signposts to his intentions, along the lines of "At this point in the chapter, I would like to pause and 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 and all other database commentators are useless, which leads to yet more unnecessary asides.

There are nuggets of useful information in 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, 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 and we were taught a number of alternatives (does anyone else remember Codasyl?) systems - relational databases and SQL were just the newest option.

Of course, once I left college and started working for a living, it wasn't long before relational databases were the only game in 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 use in our day-to-day work. But in 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 place in 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 and 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 and trying to implement a better relational query language the database vendors instead stuck with SQL and ignored the bits of the relational model which it couldn't support. For most of the examples in the book, Date gives an SQL query alongside the same query rewritten in "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 that in 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 increase in 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 says in 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 and nothing less."

There are some exciting possibilities in 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 and you have any interest in 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, 15 Sep 2005
This book is the second I read on E-R theory and SQL language.
I enjoy reading this book because of:
+ It is very clean and compact. You can understand all, even if you haven't a mathematical background
+ Some of the exposed ideas are new and can change the way you look at the E-R model and theory.
+ Date is a well-known author in this field, so you can trust a lot what he says

Look also at my review on


Great Modelling Support!, 15 Dec 2006
These books are just great and I'm impressed how the parts build up a consistent whole. I've studied volume one in detail and modelled most of it in a CASE tool. And used it as major outline for an (real) Enterprise Logical Datamodel. When compared with some commercial package's models Mr Silverstone's structures seem to have had quite a bit of influence.
Not only I have learnt a lot from these two books :)

There's more to this than a set of models, 15 Feb 2005
You might be tempted (as I was, at first) to just dip into this book and use it as a source of patterns for producing data models. And if you do that, then you will find some very useful patterns as well as saving a lot of time. But that would be a shame, because by starting at the beginning and reading the whole book, I found that as well as a very comprehensive, rigourous and coherent set of models, I also got an understanding of the underlying structures and approach. And this approach has proved to be extremely useful when dealing with any new data structures. Someone described this as 'the second data modelling book you should buy', and I agree with that.

find out what a relation really is, 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 and 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) and contrary to another poster's belief does not basically serve as propeganda on why he is great and all other comentators are wrong but that commentators who don't follow Codd's relational model are HIGHLY flawed.

Unreadable, Leaden, Wearying, 06 Jun 2006
The author C J Date may know all sorts about databases but he can't write. The prose is so leaden and full of superfluous comments that I gave up. He includes endless bizarre signposts to his intentions, along the lines of "At this point in the chapter, I would like to pause and 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 and all other database commentators are useless, which leads to yet more unnecessary asides.

There are nuggets of useful information in 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, 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 and we were taught a number of alternatives (does anyone else remember Codasyl?) systems - relational databases and SQL were just the newest option.

Of course, once I left college and started working for a living, it wasn't long before relational databases were the only game in 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 use in our day-to-day work. But in 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 place in 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 and 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 and trying to implement a better relational query language the database vendors instead stuck with SQL and ignored the bits of the relational model which it couldn't support. For most of the examples in the book, Date gives an SQL query alongside the same query rewritten in "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 that in 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 increase in 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 says in 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 and nothing less."

There are some exciting possibilities in 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 and you have any interest in 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, 15 Sep 2005
This book is the second I read on E-R theory and SQL language.
I enjoy reading this book because of:
+ It is very clean and compact. You can understand all, even if you haven't a mathematical background
+ Some of the exposed ideas are new and can change the way you look at the E-R model and theory.
+ Date is a well-known author in this field, so you can trust a lot what he says

Look also at my review on


Great Modelling Support!, 15 Dec 2006
These books are just great and I'm impressed how the parts build up a consistent whole. I've studied volume one in detail and modelled most of it in a CASE tool. And used it as major outline for an (real) Enterprise Logical Datamodel. When compared with some commercial package's models Mr Silverstone's structures seem to have had quite a bit of influence.
Not only I have learnt a lot from these two books :)

There's more to this than a set of models, 15 Feb 2005
You might be tempted (as I was, at first) to just dip into this book and use it as a source of patterns for producing data models. And if you do that, then you will find some very useful patterns as well as saving a lot of time. But that would be a shame, because by starting at the beginning and reading the whole book, I found that as well as a very comprehensive, rigourous and coherent set of models, I also got an understanding of the underlying structures and approach. And this approach has proved to be extremely useful when dealing with any new data structures. Someone described this as 'the second data modelling book you should buy', and I agree with that.

Is it worth buying a book for only one chapter?, 15 Feb 2005
Yes, it is. Because the other chapters have all sorts of useful content as well. This book covers Manufacturing, Telecommunications, Health Care, Insurance, Financial Services, Professional Services, Travel, and e-Commerce. Most companies, even if they aren't in those sectors, use the services of companies that are (or may do a little bit of them - offer insurance on their products, for example), and if you need to include these areas in your model, in more detail than was covered in volume 1 (the core Universal Data Model book), then this is the place to start. If you are in one of these areas, then the specific chapter has a lot of useful stuff (I have worked in Travel, Telecommunications and Professional Services), but it is well worth checking out the other models for ideas that can be re-used in your area.

find out what a relation really is, 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 and 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) and contrary to another poster's belief does not basically serve as propeganda on why he is great and all other comentators are wrong but that commentators who don't follow Codd's relational model are HIGHLY flawed.

Unreadable, Leaden, Wearying, 06 Jun 2006
The author C J Date may know all sorts about databases but he can't write. The prose is so leaden and full of superfluous comments that I gave up. He includes endless bizarre signposts to his intentions, along the lines of "At this point in the chapter, I would like to pause and 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 and all other database commentators are useless, which leads to yet more unnecessary asides.

There are nuggets of useful information in 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, 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 and we were taught a number of alternatives (does anyone else remember Codasyl?) systems - relational databases and SQL were just the newest option.

Of course, once I left college and started working for a living, it wasn't long before relational databases were the only game in 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 use in our day-to-day work. But in 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 place in 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 and 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 and trying to implement a better relational query language the database vendors instead stuck with SQL and ignored the bits of the relational model which it couldn't support. For most of the examples in the book, Date gives an SQL query alongside the same query rewritten in "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 that in 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 increase in 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 says in 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 and nothing less."

There are some exciting possibilities in 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 and you have any interest in 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, 15 Sep 2005
This book is the second I read on E-R theory and SQL language.
I enjoy reading this book because of:
+ It is very clean and compact. You can understand all, even if you haven't a mathematical background
+ Some of the exposed ideas are new and can change the way you look at the E-R model and theory.
+ Date is a well-known author in this field, so you can trust a lot what he says

Look also at my review on


Great Modelling Support!, 15 Dec 2006
These books are just great and I'm impressed how the parts build up a consistent whole. I've studied volume one in detail and modelled most of it in a CASE tool. And used it as major outline for an (real) Enterprise Logical Datamodel. When compared with some commercial package's models Mr Silverstone's structures seem to have had quite a bit of influence.
Not only I have learnt a lot from these two books :)

There's more to this than a set of models, 15 Feb 2005
You might be tempted (as I was, at first) to just dip into this book and use it as a source of patterns for producing data models. And if you do that, then you will find some very useful patterns as well as saving a lot of time. But that would be a shame, because by starting at the beginning and reading the whole book, I found that as well as a very comprehensive, rigourous and coherent set of models, I also got an understanding of the underlying structures and approach. And this approach has proved to be extremely useful when dealing with any new data structures. Someone described this as 'the second data modelling book you should buy', and I agree with that.

Is it worth buying a book for only one chapter?, 15 Feb 2005
Yes, it is. Because the other chapters have all sorts of useful content as well. This book covers Manufacturing, Telecommunications, Health Care, Insurance, Financial Services, Professional Services, Travel, and e-Commerce. Most companies, even if they aren't in those sectors, use the services of companies that are (or may do a little bit of them - offer insurance on their products, for example), and if you need to include these areas in your model, in more detail than was covered in volume 1 (the core Universal Data Model book), then this is the place to start. If you are in one of these areas, then the specific chapter has a lot of useful stuff (I have worked in Travel, Telecommunications and Professional Services), but it is well worth checking out the other models for ideas that can be re-used in your area.

Sets a good standard for ERD models, 15 Dec 2006
I've used this as the ERD standard book in projects, helping everyone involved to make understandable models. It's great - covers what you need, explains and motivates. If you need to get a team agree on their ERD modelling standards, buy a number of this book and make sure they're using them to guide their model language.

Exactly what it says it is, 29 Sep 2000
Excellent! I bought this several years ago and having worked as a data administrator & business modeller have found this very useful for logical data modelling, modelling issues and aspects relating to the quality of data models. So good that when I lost my copy I immediately bought another. If you are looking for a library of data model patterns it's also worth looking at the 'Data Model Resource Book' (ISBN 0-471-15364-8)

Good Consulatancy-Design review Book, 30 May 2000
I concur with those comments above, a lot of check lists and common mistakes listed (if you work in a consultancy great or are part of a design review team). I thinks that it is a job well done but is very pricy (I paid almost £70 for it in Dec '97). Why not give it an update and a bit more for the actual designer. How many times do people have to design bog-standard app tables, re-inventing the wheel ? Go the extra mile Michael & William and then you will get the 5 * you deserve. - Kevin O'Hannain

Excellent resource for any data modeller, 07 Jan 1999
This book is really a "no-nonsense guide" for data modeller. However the diagram conventions are significantly different than found on some of the popular CASE tools. But overall I keep refering to this book.

Read the title twice before buying this book.., 04 Aug 1998
Don't expect to use this book for anything but producing longdocuments for business meetings. It covers all of the annoying database design from a business prospective very well, so if you are a consultant this might help you fill up billable hours. But if you want to actually do anything with a database buy another book.

find out what a relation really is, 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 and 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) and contrary to another poster's belief does not basically serve as propeganda on why he is great and all other comentators are wrong but that commentators who don't follow Codd's relational model are HIGHLY flawed.

Unreadable, Leaden, Wearying, 06 Jun 2006
The author C J Date may know all sorts about databases but he can't write. The prose is so leaden and full of superfluous comments that I gave up. He includes endless bizarre signposts to his intentions, along the lines of "At this point in the chapter, I would like to pause and 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 and all other database commentators are useless, which leads to yet more unnecessary asides.

There are nuggets of useful information in 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, 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 and we were taught a number of alternatives (does anyone else remember Codasyl?) systems - relational databases and SQL were just the newest option.

Of course, once I left college and started working for a living, it wasn't long before relational databases were the only game in 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 use in our day-to-day work. But in 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 place in 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 and 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 and trying to implement a better relational query language the database vendors instead stuck with SQL and ignored the bits of the relational model which it couldn't support. For most of the examples in the book, Date gives an SQL query alongside the same query rewritten in "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 that in 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 increase in 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 says in 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 and nothing less."

There are some exciting possibilities in 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 and you have any interest in 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, 15 Sep 2005
This book is the second I read on E-R theory and SQL language.
I enjoy reading this book because of:
+ It is very clean and compact. You can understand all, even if you haven't a mathematical background
+ Some of the exposed ideas are new and can change the way you look at the E-R model and theory.
+ Date is a well-known author in this field, so you can trust a lot what he says

Look also at my review on


Great Modelling Support!, 15 Dec 2006
These books are just great and I'm impressed how the parts build up a consistent whole. I've studied volume one in detail and modelled most of it in a CASE tool. And used it as major outline for an (real) Enterprise Logical Datamodel. When compared with some commercial package's models Mr Silverstone's structures seem to have had quite a bit of influence.
Not only I have learnt a lot from these two books :)

There's more to this than a set of models, 15 Feb 2005
You might be tempted (as I was, at first) to just dip into this book and use it as a source of patterns for producing data models. And if you do that, then you will find some very useful patterns as well as saving a lot of time. But that would be a shame, because by starting at the beginning and reading the whole book, I found that as well as a very comprehensive, rigourous and coherent set of models, I also got an understanding of the underlying structures and approach. And this approach has proved to be extremely useful when dealing with any new data structures. Someone described this as 'the second data modelling book you should buy', and I agree with that.

Is it worth buying a book for only one chapter?, 15 Feb 2005
Yes, it is. Because the other chapters have all sorts of useful content as well. This book covers Manufacturing, Telecommunications, Health Care, Insurance, Financial Services, Professional Services, Travel, and e-Commerce. Most companies, even if they aren't in those sectors, use the services of companies that are (or may do a little bit of them - offer insurance on their products, for example), and if you need to include these areas in your model, in more detail than was covered in volume 1 (the core Universal Data Model book), then this is the place to start. If you are in one of these areas, then the specific chapter has a lot of useful stuff (I have worked in Travel, Telecommunications and Professional Services), but it is well worth checking out the other models for ideas that can be re-used in your area.

Sets a good standard for ERD models, 15 Dec 2006
I've used this as the ERD standard book in projects, helping everyone involved to make understandable models. It's great - covers what you need, explains and motivates. If you need to get a team agree on their ERD modelling standards, buy a number of this book and make sure they're using them to guide their model language.

Exactly what it says it is, 29 Sep 2000
Excellent! I bought this several years ago and having worked as a data administrator & business modeller have found this very useful for logical data modelling, modelling issues and aspects relating to the quality of data models. So good that when I lost my copy I immediately bought another. If you are looking for a library of data model patterns it's also worth looking at the 'Data Model Resource Book' (ISBN 0-471-15364-8)

Good Consulatancy-Design review Book, 30 May 2000
I concur with those comments above, a lot of check lists and common mistakes listed (if you work in a consultancy great or are part of a design review team). I thinks that it is a job well done but is very pricy (I paid almost £70 for it in Dec '97). Why not give it an update and a bit more for the actual designer. How many times do people have to design bog-standard app tables, re-inventing the wheel ? Go the extra mile Michael & William and then you will get the 5 * you deserve. - Kevin O'Hannain

Excellent resource for any data modeller, 07 Jan 1999
This book is really a "no-nonsense guide" for data modeller. However the diagram conventions are significantly different than found on some of the popular CASE tools. But overall I keep refering to this book.

Read the title twice before buying this book.., 04 Aug 1998
Don't expect to use this book for anything but producing longdocuments for business meetings. It covers all of the annoying database design from a business prospective very well, so if you are a consultant this might help you fill up billable hours. But if you want to actually do anything with a database buy another book.

Long Overdue Clarity on a Complex Subject, 30 Dec 2007
There can be no denying, I believe, that insofar as current major Database Management Systems (DBMS) are concerned, temporal data represents a significant problem: it is simply not possible to declaratively constrain the integrity of temporal data in SQL databases (or non-temporal data, even). I am not alone I am sure in having had to deal with duplicate, triplicate, quadruplicate, etc., records covering, or abutting, or overlapping on the same temporal periods. Not to mention the hoops that must be jumped through to reliably manipulate those same data.

Date, Darwen, and Lorentzos have produced a formidable work here on applying some badly needed rigid logic to the whole sphere of temporal data within databases. And that rigid logic is afforded by the Relational Model. They consider three variants on the temporal data theme as vehicles for explanation and demonstration: 1. Semitemporal with current data only, 2. Temporal with current and historical data held within the same relvars (tables), 3. Temporal with current and historical data split into separate relvars.

Temporal data is a complex area, so this book has, inevitably, had to get `down and dirty' with the detail, but the authors are clear and comprehensive throughout. A thorough familiarity with the Relational Model will help, as will any previous experience of their Relational language `Tutorial D', though they go though both in the first two introductory chapters.

We would indeed be much better off were the DBMS vendors to take serious note of the powerful logical arguments laid forth in this volume, and far from interpreting their reflections (criticisms) on NULLs, etc., as `political', I would see them only as further reaffirmations of the principles that have led them to invest so much endeavour and thought into the problems and very real deficiencies of data modelling and integrity, specifically in regard to the Relational Model. And for that we should indeed be thankful.

find out what a relation really is, 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 and 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) and contrary to another poster's belief does not basically serve as propeganda on why he is great and all other comentators are wrong but that commentators who don't follow Codd's relational model are HIGHLY flawed.

Unreadable, Leaden, Wearying, 06 Jun 2006
The author C J Date may know all sorts about databases but he can't write. The prose is so leaden and full of superfluous comments that I gave up. He includes endless bizarre signposts to his intentions, along the lines of "At this point in the chapter, I would like to pause and 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 and all other database commentators are useless, which leads to yet more unnecessary asides.

There are nuggets of useful information in 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, 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 and we were taught a number of alternatives (does anyone else remember Codasyl?) systems - relational databases and SQL were just the newest option.

Of course, once I left college and started working for a living, it wasn't long before relational databases were the only game in 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 use in our day-to-day work. But in 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 place in 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 and 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 and trying to implement a better relational query language the database vendors instead stuck with SQL and ignored the bits of the relational model which it couldn't support. For most of the examples in the book, Date gives an SQL query alongside the same query rewritten in "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 that in 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 increase in 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 says in 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 and nothing less."

There are some exciting possibilities in 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 and you have any interest in 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, 15 Sep 2005
This book is the second I read on E-R theory and SQL language.
I enjoy reading this book because of:
+ It is very clean and compact. You can understand all, even if you haven't a mathematical background
+ Some of the exposed ideas are new and can change the way you look at the E-R model and theory.
+ Date is a well-known author in this field, so you can trust a lot what he says

Look also at my review on


Great Modelling Support!, 15 Dec 2006
These books are just great and I'm impressed how the parts build up a consistent whole. I've studied volume one in detail and modelled most of it in a CASE tool. And used it as major outline for an (real) Enterprise Logical Datamodel. When compared with some commercial package's models Mr Silverstone's structures seem to have had quite a bit of influence.
Not only I have learnt a lot from these two books :)

There's more to this than a set of models, 15 Feb 2005
You might be tempted (as I was, at first) to just dip into this book and use it as a source of patterns for producing data models. And if you do that, then you will find some very useful patterns as well as saving a lot of time. But that would be a shame, because by starting at the beginning and reading the whole book, I found that as well as a very comprehensive, rigourous and coherent set of models, I also got an understanding of the underlying structures and approach. And this approach has proved to be extremely useful when dealing with any new data structures. Someone described this as 'the second data modelling book you should buy', and I agree with that.

Is it worth buying a book for only one chapter?, 15 Feb 2005
Yes, it is. Because the other chapters have all sorts of useful content as well. This book covers Manufacturing, Telecommunications, Health Care, Insurance, Financial Services, Professional Services, Travel, and e-Commerce. Most companies, even if they aren't in those sectors, use the services of companies that are (or may do a little bit of them - offer insurance on their products, for example), and if you need to include these areas in your model, in more detail than was covered in volume 1 (the core Universal Data Model book), then this is the place to start. If you are in one of these areas, then the specific chapter has a lot of useful stuff (I have worked in Travel, Telecommunications and Professional Services), but it is well worth checking out the other models for ideas that can be re-used in your area.

Sets a good standard for ERD models, 15 Dec 2006
I've used this as the ERD standard book in projects, helping everyone involved to make understandable models. It's great - covers what you need, explains and motivates. If you need to get a team agree on their ERD modelling standards, buy a number of this book and make sure they're using them to guide their model language.

Exactly what it says it is, 29 Sep 2000
Excellent! I bought this several years ago and having worked as a data administrator & business modeller have found this very useful for logical data modelling, modelling issues and aspects relating to the quality of data models. So good that when I lost my copy I immediately bought another. If you are looking for a library of data model patterns it's also worth looking at the 'Data Model Resource Book' (ISBN 0-471-15364-8)

Good Consulatancy-Design review Book, 30 May 2000
I concur with those comments above, a lot of check lists and common mistakes listed (if you work in a consultancy great or are part of a design review team). I thinks that it is a job well done but is very pricy (I paid almost £70 for it in Dec '97). Why not give it an update and a bit more for the actual designer. How many times do people have to design bog-standard app tables, re-inventing the wheel ? Go the extra mile Michael & William and then you will get the 5 * you deserve. - Kevin O'Hannain

Excellent resource for any data modeller, 07 Jan 1999
This book is really a "no-nonsense guide" for data modeller. However the diagram conventions are significantly different than found on some of the popular CASE tools. But overall I keep refering to this book.

Read the title twice before buying this book.., 04 Aug 1998
Don't expect to use this book for anything but producing longdocuments for business meetings. It covers all of the annoying database design from a business prospective very well, so if you are a consultant this might help you fill up billable hours. But if you want to actually do anything with a database buy another book.

Long Overdue Clarity on a Complex Subject, 30 Dec 2007
There can be no denying, I believe, that insofar as current major Database Management Systems (DBMS) are concerned, temporal data represents a significant problem: it is simply not possible to declaratively constrain the integrity of temporal data in SQL databases (or non-temporal data, even). I am not alone I am sure in having had to deal with duplicate, triplicate, quadruplicate, etc., records covering, or abutting, or overlapping on the same temporal periods. Not to mention the hoops that must be jumped through to reliably manipulate those same data.

Date, Darwen, and Lorentzos have produced a formidable work here on applying some badly needed rigid logic to the whole sphere of temporal data within databases. And that rigid logic is afforded by the Relational Model. They consider three variants on the temporal data theme as vehicles for explanation and demonstration: 1. Semitemporal with current data only, 2. Temporal with current and historical data held within the same relvars (tables), 3. Temporal with current and historical data split into separate relvars.

Temporal data is a complex area, so this book has, inevitably, had to get `down and dirty' with the detail, but the authors are clear and comprehensive throughout. A thorough familiarity with the Relational Model will help, as will any previous experience of their Relational language `Tutorial D', though they go though both in the first two introductory chapters.

We would indeed be much better off were the DBMS vendors to take serious note of the powerful logical arguments laid forth in this volume, and far from interpreting their reflections (criticisms) on NULLs, etc., as `political', I would see them only as further reaffirmations of the principles that have led them to invest so much endeavour and thought into the problems and very real deficiencies of data modelling and integrity, specifically in regard to the Relational Model. And for that we should indeed be thankful.


A good quality overview but light on explanatory power, 11 Oct 1999
This is probably the best introductory volume on data modelling available. Barker concisely covers almost all entity relationship types and how they may be derived from the business. The main weakness with the book is the cursory treatment given to the process of extrapolating the logical models into the physical.