16. Retail chains want to ensure that every time a customer returns to purchase something, the record of that purchase can be matched with previous data of that customer. What objects that consumers offer use help the retailers in that regard?

17. Increasingly, corporate databases are updated by the corporations customers rather than their employees. How so?

18. can you think of an industry that would not benefit from the promise of data warehouse, explain?

19. shouldnt those who build data warehouse trim the data before they load it to data warehouse? Why do they usually not cut any data from transactions?