The questions can come in any order, so make sure you are selecting right option for all questions.
1. If R1 (P, Q) and R2 (Q, S) are decompositions of a given relation R (P, Q, S), and the join of R1 and R2 over Q is equal to relation R, what can be concluded?
(b) R1 and R2 are a lossless decomposition of R, and a join dependency exists.
2. A relation is said to have a join dependency if it can be recreated by joining multiple sub-relations and each of these sub-relations has a subset of the attributes of the original relation. This is an example of:
(c) Fifth normal form (5NF)
3. Why is it important to decompose tables in a way that satisfies all rules up to 4NF before reaching 5NF?
(a) To ensure lossless join decomposition
4. A relation has a join dependency if it can be reconstructed by joining multiple sub-relations, and each of these sub-relations has a subset of the attributes of the original relation.
5. Which normal form addresses the join dependency in database normalization?
(c) Fifth normal form (5NF)
6. In Fifth Normal Form (5NF), a relation should be:
(d) Already in 4NF and cannot be further non-loss decomposed (join dependency)
7. When is a Join Dependency considered trivial?
(b) When one of the relation schemas in a join dependency is equal to the original relation
8. What is TRUE about 5NF?
