Normal Form
Q21.
Let the set of functional dependencies F=\{QR\rightarrow S,R\rightarrow P,S\rightarrow Q\} hold on a relation schema X = (PQRS). X is not in BCNF. Suppose X is decomposed into two schemas Y and Z where Y = (PR) and Z = (QRS). Consider the two statements given below: I. Both Y and Z are in BCNF II. Decomposition of X into Y and Z is dependency preserving and lossless. Which of the above statements is/are correct?Q22.
Consider a relational table R that is in 3NF, but not in BCNF. Which one of the following statements is TRUE?Q23.
The set of attributes X will be fully functionally dependent on the set of attributes Y if the following conditions are satisfied.Q24.
Consider the following dependencies and the BOOK table in a relational database design. Determine the normal form of the given relation. ISBN \rightarrow Title ISBN \rightarrow Publisher Publisher \rightarrow AddressQ25.
Given the following two statements: S1: Every table with two single-valued attributes is in 1NF, 2NF, 3NF and BCNF S2 : AB\rightarrowC, D\rightarrow E, E\rightarrowC is a minimal cover for the set of functional dependencies AB\rightarrowC, D\rightarrowE, AB\rightarrow E,E\rightarrowC. Which one of the following is CORRECT?Q28.
Consider the relation X(P,Q,R,S,T,U) with the following set of functional dependencies F= {{P,R}\rightarrow{S,T}, {P,S,U}\rightarrow{Q,R} } Which of the following is the trivial functional dependency in F^{+}, where F^{+} is closure of F ?Q30.
Relation R has eight attributes ABCDEFGH. Fields of R contain only atomic values. F=\{CH\rightarrow G, A\rightarrow BC,B\rightarrow CFH,E\rightarrow A,F\rightarrow EG\} is a set of functional dependencies (FDs) so that F^{+} is exactly the set of FDs that hold for R. How many candidate keys does the relation R have?