As your business has grown, you have found it increasingly hard to keep track of your mailings to your customers without using a database, so the time has come to use a database, and with it, mail merge technology. You turn to your friend Thomas, since he has been doing mail merges for a long time and can guide you in the use of this tool in Microsoft Word. Where does Thomas tell you the merge field names go in your data source?

Jason works as an accountant in a department store. he needs to keep a daily record of all the invoices issued by the store. which file naming convention would him the most?

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)?

Does read theory have answers keys ?