Given the questions of funeutional dependency and the table below answer (5 poin

Question

Given the questions of funeutional dependency and the table below answer (5 points) Function Dependency OFD). Let R be a relation schema, and let a and B be subset of R. The functional dependency a B. hold on schema R if for all tuples t1 and 12 in r(R) such that tila] 20a], it is also the cse 2. Wi aut Relational s R-(Loan-number, customer-name, Amount), and the vabe,ro below: Loan-number Customer-name Amount Pump Jones 150,000 Jackson 165 000 L-102 L-101 Johnson 150,000 L-104 Smith 280,000 1. Does function dependency, Loan-number- Customer-name hold? Explain why? 2. What function dependency does hold on the table above? Explain why?

Explanation / Answer

ANS(1):In Relation R Functional dependency Loan-number --> Customer-name does not hold

because t1[Loan-number] = t2[Loan-number] but t1[Customer-name] != t2[Customer-name].

Means In Loan-number attribute there are 2 tuples which are same L-101,but for these 2 tuples Customer-number are different jones and johnson. A single Loan-number(L-101) can not determine 2 different Customer-names(jones and johnson).So this functional dependency can not hold.

ANS(2): The following functinal dependencies hold for the Relation R.

1.Loan-number --> Amount

becuse t1[Loan-number] = t2[Loan-number] and t1[Amount] = t2[Amount].

For Attribute Loan-number there are 2 tuples which are same(L-101) and for these 2 tuples ,there are same 2 tuples present in Amount Attribute.So this functional dependency can preserve.

2.Customer-name --> Amount

This functional dependency preserve because in Customer-name attribute all the tuples are different so they can determine the attribute Amount whether it's having same tuples or different ,It's totally depedent on Customer-name.

3.Amount --> Loan-number

This function dependency can also preserve ,because Amount can also determine Loan-number.

t1[Amount] = t2[Amount] and t1[Loan-number] = t2[Loan-number] .

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