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Option 4 : all of his/her dependents

Explanation:

Example:

Employee Relation:

EmpID

empName

empAge

e1

A

20

e2

B

25

e3

C

24

 

Dependent Relation:

depID

eID

depName

Age

d1

e1

X

30

d2

e1

Y

25

d3

e1

Z

20

d4

e2

P

18

d5

e2

P

17

d7

e3

Z

35

 

R1=ΠempId (employee⋈(empId = eID)∧(empAge ≤ depAge)dependent)

Output : e1,e3

R2=ΠempId(employee)

Output: e1,e2,e3

R = R2 - R1= {e1,e2,e3} - {e1,e3} = e2

  • e2 is output that is saying that set of empIds of employees whose age is greater than that of all of his/her dependents.
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