Consider the relation R with attributes: A, B, C, D, E, and F Let S be...
Here's a relation (R), its attributes and its functional dependencies (F): R(A, B, C, D, E) C D → B A → D D → C E → C What is the closure of AB ({AB}+)? What is the closure of F (F+)? [ set of closures for all LHS][each LHS on one line] What is the minimal set (cover) for F? Provide a key for relation R (a minimal set of attributes that can determine all attr.) Decompose the...
Consider a relation schema R with attributes ABCDEFGH with functional dependencies S: S={B→CD, BF→H, C→AG, CEH→F, CH→B} Employ the BCNF decomposition algorithm to obtain a lossless decomposition of R into a collection of relations that are in BCNF. Make sure it is clear which relations are in the final decomposition and project the dependencies onto each relation in that final decomposition.
This question is from the subject: Database Systems QUESTION 8 Consider the relation R(A,B,C,D,E,F) with FDs A -> C,B->D, C-> E, D -> F. Consider the BCNF status of R. Which of the following could be correct given the information above? 1. Ris in BCNF already. 2. Ris not in BCNF. It must be divided into R1(A,C,E) with FDs A->C, C-> E, and R2(B,D,F) with FDs B -> D, D -> F. 3. R is not in BCNF. It must...
Question 1: Functional Dependencies [7 marks Consider a relation R on attributes (A, B, C, D, E, F,G, H) and the following functional dependen- cies. B →G C →D DE →GC → EF DEF → H (a) What is the closure of [F, G, Hy? (b) List all of the candidate keys of R under the dependencies above. (c) List all of the FDs above that are 3NF violations (d) List all of the FDs above that are BCNF violations....
Given a schema R (A, B, C, D, E, F)and a set Fof functional dependencies {A →B, A →D, CD →E, CD →F, C →F, C →E, BD →E}, find the closure of the set of functional dependencies ?+
Consider a relation R with ve attributes A, B, C, D, and E. You are given the following functional dependencies: A->B, BC->E, and ED->A. (a) List all keys for R. (10 points) (b) Is R in BCNF? If it is, explain why. If is not, decompose it into a collection of BCNF relations. (20 points) (c) Is R in 3NF? If it is, explain why. If it is not, convert it into a collection of 3NF relations. (20 points)
Consider the following relation R= {A, B, C, D, E} and the following set of functional dependencies F={ A → BC CD → E B + D E + A} Give a lossless, dependency-preserving decomposition into 3NF of schema R
Consider the schema R = (A, B, C, D, E) and let the following set F of functional dependencies holdforR: F = {A -> BC, CD -> E, C -> A, B -> D,} 1) Prove or disprove ADE is in the closure of F. A proof can be made by using inference rules IR1 through IR3. A disproof should be done by showing a relational instance (counter example) that refutes the rule. 2) What are the candidate keys of...
Consider the following relation: R(A,B,C,D,E) The following set of functional dependencies are ture on the relation R: FD: AB -> E, E -> D, AD -> C Which of the following sets of attributes does not functionally determine C? AC ABE BD AE AB
Again, suppose we have a relation on attributes A, B, C, D, E, and F, and these functional dependencies hold: S = { B → DE, BF → C, CF → B, DF → AE }. (a) Does it follow from S that B → A? (b) Does it follow from S that CF → E? (c) Does it follow from S that DF → B? (d) Does it follow from S that BD → C? (e) Does it follow...