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 ?+
closure of the set of functional dependencies can be defined as set of attributes which can be functionally determined from it.
A+ = ABDE
CD+ = CDEF
C+ = CFE
BD+ = BDE
Given a schema R (A, B, C, D, E, F)and a set Fof functional dependencies {A...
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 schema R-(A,B.C,D,E) and the following set F of functional dependencies holds on R ABC CD-E B- D E-A Problem 2. Suppose that we decompose the relation schema R into R, -(A, B, C) and R, (C, D,E). Show that this decomposition is not a lossless-join decomposition.
1. Given the schema R(A,B,C,D,E) with the functional dependencies F = { A → C,D D B, E B, C + D, E E → B,C } Is this schema in BCNF? If it is, prove it. If not, find a BCNF decomposition and then prove that the decomposition is in BCNF. You must prove each step carefully.
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,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
Q3: Given a relational schema R = {A,B,C,D,E,F,G,H,1,J,K} and a set of functional dependencies F {A B C D E, E F G H I J,AI →K} and a key(R) = AI = 1. Is R in BCNF? If yes, justify your answer [5 points] 2. If no, explain why and decompose R for two levels only [10 points] 3. Check whether the decomposition in step 2 dependency preserved or not [5 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
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...
Given the schema S= < { A,B,C,D,E,G,H }, F>, where F represents the following dependencies: AB→D A→D E→B E→C G→C E→A EB→GH H → A Find a minimal cover for this schema. Find a key for this schema. Find a third normal form decomposition for this schema. Find a BCN form decomposition for this schema.
Consider the relation R with attributes: A, B, C, D, E, and F Let S be a set of functional dependencies in R such that S = { A-> B, CD-> E, C-> D]. Which of these attributes are in the closure of [C, F)?