Once displayed, the database graph drawing is an
invaluable tool: the drawing shows objects in context of
other objects and also highlights objects that have a
central role to the overall database schema design. In
addition, when the user selects objects (by clicking on
them), the graph shows the objects in relation to other
objects by highlighting all related edges and objects.
Related objects may be child objects or parent objects.
Child objects are objects dependant upon the selected
object, while parent objects are objects the selected object
is dependent upon. Graphically showing all objects and
showing relationships among objects is extremely
important and helpful in understanding a database
schema.