c) Consider the following relation R with the functional dependencies: AC B, AD E, AB C, E→F, BC A, and BD. R A В C D E F 1 3 4 6. 7 8. 9 10 Is {AB, BC, ABDE, EF} a lossless-join decomposition? Explain. Is the decomposition {ABC, ACDE, ADF} lossless join? Determine the projection of the set of functional dependencies of R onto ABC, ACDE, and a) c) ADF. Is this decomposition dependency preserving?

c) Consider the following relation R with the functional dependencies: AC B, AD E, AB C, E→F, BC A, and BD. R A В C D E F 1 3 4 6. 7 8. 9 10 Is {AB, BC, ABDE, EF} a lossless-join decomposition? Explain. Is the decomposition {ABC, ACDE, ADF} lossless join? Determine the projection of the set of functional dependencies of R onto ABC, ACDE, and a) c) ADF. Is this decomposition dependency preserving?

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

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Similar questions

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Consider the relation R(O,P,X,Y,E, S); FDs={ O=P, XY=O, OE=S, EY=X, PY=X} What is the dependency preservation property for a decomposition? Why is it important? Decompose the relation into BCNF relation. What is the lossless (or nonadditive) join property of a decomposition? Why is it important? Determine whether each of the decompositions has the lossless join property with respect to F and conclude for the whole decomposition Determine whether each of the decompositions has the dependency preserving property with respect to FD and conclude for the whole decomposition
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Let R(ABCDEFG) be a relation and F={A -> C, A-> D, B->F, E->F, F->G}a. Show example of lossless join decomposition of R into three tables R1, R2 and R3 and demonstrate that this decomposition is lossless using chase algorithmb. Find one key for this scheme and prove that it is a key using closure algorithm and definition of a key.
J 1 Let R(A, B, C, D, E, F) be a relation schema, and let S = {A → B, BC → D, E → C, D →A, B → D} be a set of functional dependencies. Use the Nonadditive Join Test for Binary Decomposition to determine if the following decomposition is lossless.
1. A known relationship mode of R (U, F), U= (A, B, C, E, F, G, H, I, J, G); F={AB->E,ABE->FG, B->FI, C->J, CJ->I, G->H}; find the minimum cover of F, then use theNormal Form decomposition algorithm to decompose this mode to 3NF, and check if thedecomposition has the nonadditive join property.
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Consider a relation R(A,B,C,D,E) with functional dependencies AB→C, A→D, and D→E. (a) What are the keys for R?(b)What is the closure A, that is A+ ? What is the closure AB, that is (AC)+ ?
Problem 4.3 (**) Assume that relation PROJ is fragmented as in Problem 4.1.Furthermore, relation ASG is indirectly fragmented asASG1 = ASG PNO PROJ1ASG2 = ASG PNO PROJ2and relation EMP is vertically fragmented asEMP1 = ENO,ENAME(EMP)EMP2 = ENO,TITLE(EMP)vnineTransform the following query into a reduced query on fragments:SELECT ENAMEFROM EMP NATURAL JOIN ASG NATURAL JOIN PROJWHERE PNAME = "Instrumentation".
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