Question 4
Marks : +2 | -2
Pass Ratio : 100%
What does the following relational operation perform?
Explanation: If a relational-algebra expression E has arity n, then the above expression returns the result of expression E under the name X, and with the attributes renamed to A1 , A2 , …., An.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
What does the following relational algebra expression do?
Explanation: The above expression finds all the tuples in loan wherever the amount is greater than 1200. Because the condition specifies that the amount should be greater than 1200.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Πcustomer_name, loan_number, amount (borrower ⋈loan)
Explanation: The above relational algebra expression finds the customer_name, loan_number and amount from the natural join of borrower and loan as the attributes are written next to the project symbol and the relation to be extracted from is mentioned in the parentheses which is the natural join of borrower and loan.