Relationship between type and table hierarchies
Every table in
a table hierarchy must be assigned to a named row type in a corresponding
type hierarchy. The following figure shows an example of the relationships
that can exist between a type hierarchy and table hierarchy.
Figure 1. Example of the relationship
between type hierarchy and table hierarchy
However, you
can also define a type hierarchy in which the named row types do not
necessarily have a one-to-one correspondence with the tables in a
table hierarchy. The following figure shows how you might create a
type hierarchy for which only some of the named row types have been
assigned to tables.
Figure 2. Example
of an inheritance hierarchy in which only some types have been assigned
to tables