Computer Sciences > GATE 2014 SET-3 > Relational Algebra
Consider the relational schema given below, where empId 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, empId, 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
employee (empId, empName, empAge)
dependent (depId, empId, 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
Explanation
Correct : d
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