Relational Model 1. Explain why data independence is an important property in a DBMS. 2. Consider the relations Students, Faculty, Courses, Rooms, Enrolled, Teaches, and Meetsin defined below. Students(sid: string, name: string, login: string, age: integer, gpa: real) Faculty(fid: string, fname: string, sal: real) Courses(cid: string, cname: string, credits: integer) Rooms(rno: integer, address: string, capacity: integer) Enrolled(sid: string, cid: string, grade: string) Teaches(fid: string, cid: string) MeetsIn(cid: string, rno: integer, time: string) a) List three foreign key (to primary key) constraints among these relations. b) Give three examples of tuple or domain constraints over these relations that are not primary key or foreign key constraints. For each of your constraints in (a) and (b), describe in one sentence why your constraint is necessary