1. What does the term unnormalized relation refer to? How did the normal forms
develop historically from first normal form up to Boyce-Codd normal form?
2.. Define first, second, and third normal forms when only primary keys are considered. How do the general definitions of 2NFand 3NF, which consider all keys of a relation, differ from those that consider only primary keys? 3. What undesirable dependencies are avoided when a relation is in 2NF?