Question-31

DBMS

Consider the relation Student (name, sex, marks), where the primary key is shown underlined, pertaining to students in a class that has at least one boy and one girl. What does the following relational algebra expression produce? (Note: \(\rho\) is the rename operator).

\[\pi_{name}\{\sigma_{sex=female}(\text{Student})\} - \pi_{name}(\text{Student} \Join_{(sex=female \wedge x=male \wedge marks \leq m)} \rho_{n,x,m}(\text{Student}))\]