If necessary, add the Developer tab to the ribbon. Create an absolute macro on the TicketOrder worksheet that will clear the contents of all cells containing data entered by the user. This includes the cell ranges B4:B6, B10:B15, and B18:B19. Select all three ranges before clearing the contents. Make cell B4 the active cell after the macro is run. Name the macro ClearData and assign the letter d as the shortcut key. After creating the macro, click the Undo button to undo the change you made.

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?