Database Management System
Q31.
Consider the schema R(A,B,C,D) and the functional dependencies A \rightarrow B and C \rightarrow D. If the decomposition is made as R_{1}(A, B) and R_{2}(C, D), then which of the following is TRUE?Q32.
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?Q33.
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 AddressQ35.
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 ?Q38.
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?Q39.
Let R (A, B, C, D, E, P, G) be a relational schema in which the following functional dependencies are known to hold: AB \to CD, DE \to P, C \to E, P \to C and B \to G. The relational schema R isQ40.
Consider the following relational schema: Suppliers(sid:integer, sname:string, city:string, street:string) Parts(pid:integer, pname:string, color:string) Catalog(sid:integer, pid:integer, cost:real) Assume that, in the suppliers relation above, each supplier and each street within a city has a unique name, and (sname, city) forms a candidate key. No other functional dependencies are implied other than those implied by primary and candidate keys. Which one of the following is TRUE about the above schema?