Description of the illustration

Table Orders. There are a group of tables below this text with the dates below the tables: Jan 2006, Feb 2006. To the right of this is the text: - RANGE(order_date) - Primary key order_id.

Table LINEITEMS. After this text is a duplicate group of tables, connected to the top group: Jan 2006, Feb 2006. To the right of this is the text: - RANGE(order_date), - Foreign key order_id.

There is an arrow from the top group to the bottom group with this text next to it: - Redundant storage of order_date, - Redundant maintenance.