The following relation records the age of 500 employees of a company, where empNo (Indicating the employee number) is the key:
empAge(empNo, age)
Consider the following relational algebra expression:
πempNo(empAge ⋈ (age>age1) ρempNo 1, age1(empAge))
What does the above expression generate?
1
Employee numbers of only those employees whose age is the maximum.
2
Employee numbers of all employees whose age is not the minimum.
3
Employee numbers of only those employees whose age is more than the age of exactly one other employee.
4
Employee numbers of all employees whose age is the minimum.
5
Question Not Attempted