Consider the relational schema given below, where eId of the relation dependent is a foreign
key referring to empId of the relation employee. Assume that every employee has at least one
associated dependent in the dependent relation.
Employee (empId, empName, empAge)
Dependent(depId, eId, depName, depAge)
Consider the following relational algebra query:
ΠempId(employee)-ΠempId (employee⋈(empId = eID)∧(empAge ≤ depAge)dependent)
The above query evaluates to the set of empIds of employees whose age is greater than that of
1. some dependent.
2. all dependents
3. some of his/her dependents
4. all of his/her dependents