Part V of this book contains the main discussion of the new features of Oracle8 that are relevant to PL/SQL.

• Chapter 18, Object Types , describes the Oracle "object-relational model" and how the object features work.

• Chapter 19, Nested Tables and VARRAYs , examines the two types of "collection" structures introduced in Oracle8.

• Chapter 20, Object Views , describes object views, which let you use object features with conventional relational tables.

• Chapter 21, External Procedures , discusses how you can call out to non-PL/SQL programs from within Oracle.