Check all that apply. We consider the constraint: A class start time must be before its end time. The constraint is ... Dynamic Static Structural/syntactic Semantic Question 7 (10 points) Check all that apply. We consider the constraint: In teaching assignment table that assigns professors to courses, each individual assignment should correspond to exactly one professor and one course. The constraint is ... Structural/syntactic Semantic Static Dynamic Question 8 ( 10 points) MySQL SQL and PostgreSQL permit to define the same reactive and referential constraints. True False We consider the table Teaching below. Check all statements that are True. We consider an ideal DBMS that would enforce all reactive constraints. CREATE TABLE Teaching ( Profld INTEGER, CrsCode CHAR (6), Semester CHAR (6), PRIMARY KEY (CrsCode, Semester), FOREIGN KEY (CrsCode) REFERENCES Course, FOREIGN KEY (Profid) REFERENCES Professor (Id)) If we update a semester in Teaching, nothing happens in Professor. If we delete a professor in Professor, nothing happens in Teaching. If we delete a course (CrsCode) in Course, we set to null the value of CrsCode in Teaching. If we delete a course (CrsCode) in Course, we delete the data about this course in Teaching. Question 10 (10 points) A view exists physically. True False