Summary of Relationship Representations
Figure H-32 summarizes the representations of record relationships. Trees can be represented using sequential
lists (although we did not discuss this approach), linked lists, or indexes. Sequential lists are not
used in DBMS products. A simple network can be decomposed into trees and then represented or it can
be represented directly using either linked lists or indexes. Finally, a complex network can be decomposed
into a tree or a simple network (using intersection records) or it can be represented directly using
indexes.