You are responsible for maintaining Windows workstation operating systems in your organization. Recently, an update from Microsoft was automatically installed on your workstations that caused an in-house application to stop working.
To keep this from happening again, you decide to test all updates on a virtual machine before allowing them to be installed on production workstations.
Currently, none of your testing virtual machines have a network connection. However, they need to be able to connect to the update servers at Microsoft to download and install updates.

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)?