why the answer

courses.cs washington.edu tal14 CSE 414 Introduction to Daab.. httpsu/lcourses.cs d) (6 points total) Given the following statistics, indicate whether having an unclustered index would ever perform worse than doing a sequential scan for the query. You will get 2 points for each correct answer, -1 point for incorrect one, and o for no answer. Minimum you will get for this question is o. SELECT R,a FROM R WHERE R"a = 42 i) B(R)-6,000, T(R)-100,000, V(R, a) -30 Yes ii) B(R) = 3,000,t(R) = 600,000, V(R, a)-300 Yes iii) B(R) = 3,000, T(R) = 100,000, V(R, a) = 30 Yes No