• Not only in role
• Size
• Video server example
• Complexity
• Ford Puma™ example
• Ford staff organised by production line and car
• e.g. Each staff member answers to a 'part' manager (engines, bodyshell, chassis) and a 'car' manager (Puma, Mondeo, Ka)
• Expense
• User profiles and demands

We've seen that databases are used in a variety of contexts. Those roles imply properties of each of the systems. An interlinked text-only database (such as Unix/Linux's MAN pages) will require much less storage than a video archive.

Some databases are perceptually more complex. Ford's staff management model would be represented as a matrix (in this case 2 dimensional). Computers are very good at organising multi-dimensional space.