Dan is a small business owner who depends on his computer to keep track of customer and sales data. He is investigating storage options because it is critical for him to ensure that his data is safe in the event of a computer failure. As Dan is very concerned about maintaining the security of his business data, he should look for an external hard drive that comes with built-in .

What type of file does a cookie place on web site visitors' computers so that web site managers can customize their sites to their visitors' preferences?

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)?

What is the most important for you to choose before you build a network?