Consider a database system for a baseball organization. The data requirements are summarized as follows: The personnel involved include players, coaches, managers, and umpires. Each is identified by a unique personnel id. They are also described by their first and last names along with the date and place of birth. Players are further described by other attributes such as their batting orientation (left, right, or switch) and have a lifetime batting average (BA). Within the players group is a subset of players called pitchers. Pitchers have a lifetime ERA (earned run average) associated with them Teams are uniquely identified by their names. Teams are also described by the city in which they are located and the division and league in which they play Teams have one manager, a number of coaches, and a number of players. It is assumed that each manager cannot manage more than one team and each coach cannot coach for more than one team