What is the screen size for a typical tablet?

When a user is informed that his or her input is not in the correct form, what additional feedback should be given at the same time?

What will be an ideal response?

Consider the expression

Suppose that there are the following access paths:
(a) An unclustered hash index on StudId
(b) An unclustered hash index on Semester
(c) An unclustered hash index on Grade

Which of these access paths has the best selectivity and which has the worst? Compare the selectivity of the worst access path (among the above three) to the selectivity of the file scan.