The purpose of these exercises is to give some idea of the scope of the chapters to come, and also perhaps to test the extent of your existing knowledge. They can’t be answered from material in the present chapter alone.

1.1 Is it true that the relational model doesn’t require relvars to be in any particular normal form?

1.2 Should data redundancy always be eliminated? Can it be?

1.3 What’s the difference between 3NF and BCNF?

1.4 Is it true that every “all key” relvar is in BCNF?

1.5 Is it true that every binary relvar is in 4NF?

1.6 Is it true that every “all key” relvar is in 5NF?

1.7 Is it true that every binary relvar is in 5NF?

1.8 Is it true that if a relvar has just one key and just one other attribute, then it’s in 5NF?

1.9 Is it true that if a relvar is in BCNF but not 5NF, then it must be all key?

1.10 Can you give a precise definition of 5NF?

1.11 Is it true that if a relvar is in 5NF, then it’s redundancy free?

1.12 What precisely is denormalization?

1.13 What’s Heath’s Theorem, and why is it important?

1.14 What’s The Principle of Orthogonal Design?

1.15 What makes some JDs irreducible and others not?

1.16 What’s dependency preservation, and why is it important?

1.17 What’s the chase?

1.18 How many normal forms can you name?