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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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