dbms

Consider the following database schema and example instance: Course Student dept credit cs 1 BOY Enroll Preze 2011 A 30 10 PHYSSE MY Hints: - Primary keys are underlined with red color. - The attribute cid and sid of relation Enroll is a foreign key to relations Course and Student, respectively. - All the attributes cid and pid (except for the one in Course) are a foreign key to relation Course. Write Relational Algebra queries to retrieve the following information: 1. Find the names of all the students enrolled in course 'EE401. 2. Write a relational algebra expression that for each student the title of the courses he/she has received an 'A' grade in. Return this information as tuples (name, title) where title and name represent the course title and student name, respectively. 3. Find the students (sid and name) that have taken at least one of the prerequisite(s) of course CS595' and got an *A grade in this prerequisite course. 4. List all the students (sid and name) who never got a grade lower than 'B' (grade point below 3.0). 5. List the titles of all the courses that student *Alice' has not taken. 6. List all the students and their GPA (result schema: sid and GPA). The GPA is calculated by summing up the grade of each course multiplied the number of credits for the course and then dividing the result by the total number of credits the student has taken. K