Would a major a major retailer such as Amazon.com or Wal-Mart be better off using a data warehouse instead of an operational database

1)Would a major a major retailer such as Amazon.com or Wal-Mart be better off using a data warehouse instead of an operational database for its day-to-day transactions? Why or Why not? Please justify your answer.

2)Would a major a major retailer such as Amazon.com or Wal-Mart be better off using a NoSQL database instead of an relational database for its day-to-day transactions? Why or Why not? Please justify your answer.