to
check a relation, whether it is in bcnf or not, check all the
determinent of the dependency, if all the determinent are superkeys
(deriving all attributes of relation) then its in bcnf otherwise
not.
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...
Q3: Given a relational schema ? = {?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?} and a set of functional dependencies ? = {? → ? ? ? ?, ? → ? ? ?, ? → ?, ? ? → ?} and a key(R) = AI 1. Is R in BCNF? If yes, justify your answer. 2. If no, explain why and decompose R for two levels only. 3. Check whether the decomposition in step 2 dependency...
Language: SQL - Normalization and Functional
Dependencies
Part 4 Normalization and Functional Dependencies Consider the following relation R(A, B, C, D)and functional dependencies F that hold over this relation. F=D → C, A B,A-C Question 4.1 (3 Points) Determine all candidate keys of R Question 4.2 (4 Points) Compute the attribute cover of X-(C, B) according to F Question 43 (5 Points) Compute the canonical cover of F.Show each step of the generation according to the algorithm shown in class....
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.
Write the complete proof.
Consider the relational schemas given below and the respective sets of functional dependencies valid in the schemas For each one of the relational schemas, determine the highest normal form, which is valid for a schema. Justify your answer If a schema is not in BCNF, then decompose it into a minimum number of schemas so that each one of them is in BCNF. Justify your answers. Justification must include the derivations of minimal keys from the...
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.
Given R = (A, B, C, D, E, G, H, I) and the set F of functional dependencies: BDEI → GH EG → AI DH → CE I → BD use the BCNF algorithm to generate a database design. Is your design dependency-preserving? Why or why not?
Given the following Schema S = (R, FD) where R = (A, B, C, D, E, F) and FD contains the following dependencies: A -> BC B ->C C -> D D ->E C -> E E -> F DE -> F C -> F 1. Find a minimal cover of F 2. Find a key for the schema 3. Find a 3N decomposition of the schema that satisfies the lossless join decomposition and dependency preservation properties 4. Find a...
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...
Q2: Explain with example the difference between super keys and functional dependencies in relational databases. Show how to find a key (super/candidate) for the following functional dependencies [10 points]: R = {A, B, C, D, E, F, G, H, I, J, K,L,M} F {A B C D E, E F G H I J,AI →K,AL →M} =
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 ?+