And then: What did u mean when wrote "SYSTEM SEGMENT"
What is it?
This is TABLE/INDEX ... segment in system tablespace?

This type of segment doesn't exists in Oracle database.

SQL> select distinct SEGMENT_TYPE from dba_segments;

SEGMENT_TYPE
------------------
CACHE
CLUSTER
INDEX
LOBINDEX
LOBSEGMENT
ROLLBACK
TABLE
TEMPORARY

If u read about this type of segment in book "Introduction ... Z030..." then u have to know
that the book is collection of errors, typos and conceptual mistakes.
Read this book very carifully.