consider the schema R-(A,B.C,D,E) and the following set F of functional dependencies holds on R ABC...
Consider the schema R=(A, B, C, D, E) and let the following set F of functional dependencies hold for R: F= {A → BC, CD → E, B D } Problem 3 Suppose that the schema R=(A, B, C, D, E) is decomposed into R/ - (A, B, C) and R=(A, D, E). Show if this decomposition is a lossless decomposition with respect to the given set of functional dependencies F.
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} F = { A → BC CD → E B → D E → A} Give a lossless, dependency-preserving decomposition into 3NF of schema R
Consider a relational schema R(A, B, C, D) with a set of functional dependencies F = { D --> AB, C --> B, CD --> A, AD --> B, B --> A } a. Compute { B, C }+ b. Show that { C, D } is a candidate key of R. c. Is { R1(A, B, C), R2(C, D ) } a lossless-join decomposition? Why? d. Compute a minimal cover Fmin of F.
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 relation schema R(T, E, C, D, Y) and the following set of F of functional dependencies: CY à E E à Y DY à T CT à D The relation R decomposes into R1(C, Y, E), R2(C, T, D). 1. Is this decomposition lossless-join? _________________Blank 1 True False 2. Is this decomposition dependency preserving? ? _____________Blank 2 True False
Consider the following relation R(A,B,C,D,E,G) and the set of functional dependencies F = { A → BCD BC → DE B → D D → A} Give a 3NF decomposition of the given schema based on a canonical cover
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 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.
5c. Consider the relation R(ABCDE) with the set of functional dependencies F={BE→D, DE→A, AD→C, B→E}. Using decomposition, find a lossless, dependency preserving, BCNF set of relations for R, if such exists. Be sure to identify the projections of the functional dependencies onto the resulting relations at each stage of the decomposition.
Suppose that you decompose a schema R (A, B, C, D, E) into two schemas as below: R1 (A, B, C) R2 (C, D, E) Show that this decomposition is not a lossless join decomposition. Hint: Take a suitable Relation, r, for the Schema R and show that r is a lossy join decomposition.