Multilevel Collection Types : Introduction « Collections « Oracle PL/SQL Tutorial

A collection type whose elements are also a collection type is known as a multilevel collection type.

The following list shows the valid multilevel collection types:

1. A nested table containing a nested table type
2. A nested table containing a varray type
3. A varray containing a varray type
4. A varray containing a nested table type
5. A varray or nested table of an object type that has an attribute that is a varray or nested table type