Tuple Relational Calculus

Consider a relational database schema with two relations $R(P, Q)$ and $S(X, Y)$. Let $E=\{\langle u\rangle \mid \exists v \exists w\langle u, v\rangle \in R \wedge\langle v, w\ran...

Consider two relations describing teams and players in a sports league: * teams (tid, tname): tid, tname are team-id and team-name, respectively * players(pid, pname, tid): pid, pn...

Consider two relations describing teams and players in a sports league: $\bullet$ teams(tid, tname): tid, tname are team-id and team-name, respectively. $\bullet$ players(pid, pnam...

Consider the following relational schema. Students( rollno: integer, sname: string) Courses( courseno: integer, cname: string) Registration( rollno: integer, courseno: integer, per...

Consider The Following Relational Scheme Student ( school-id, sch-roll-no , sname, saddress) School ( school-id , sch-name, sch-address, sch-phone) Enrolment ( school-id, sch-roll-...

Which of the following tuple relational calculus expression(s) is/are equivalent to $$\forall t \in r \left(P\left(t\right)\right)$$? I. $$\neg \exists t \in r \left(P\left(t\right...

Consider the relation employee(name, sex, supervisorName) with name as the key, supervisorName gives the name of the supervisor of the employee under consideration. What does the f...

Which of the following relational query languages have the same expressive power? I) Relational algebra II) Tuple relational calculus restricted to safe expressions III) Domain rel...

Which of the following relational calculus expressions is not safe?

The relational algebra expression equivalent to the following tuple calculus expression: $$\left\{ {t|t \in r \wedge \left( {t\left[ A \right] = 10 \wedge t\left[ B \right] = 20} \...