Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL> drop table t;

Table dropped.

SQL>
SQL> create table t
  2  nologging
  3  compress
  4  pctfree 0
  5  as
  6  select 'ABCDEFGHIJKLMNOP' col1
  7  from   dual
  8  connect by level <= 10000
  9  /

Table created.

SQL> commit
  2  /

Commit complete.

SQL>
SQL> select blocks
  2  from   user_segments
  3  where  segment_name = 'T' and
  4         segment_type = 'TABLE'
  5  /

    BLOCKS
----------
        16

SQL>
SQL> update t
  2  set    col1 = col1
  3  /

10000 rows updated.

SQL> commit
  2  /

Commit complete.

SQL>
SQL> select blocks
  2  from   user_segments
  3  where  segment_name = 'T' and
  4         segment_type = 'TABLE'
  5  /

    BLOCKS
----------
        80