Query dba_extents for segment name : dba_extents « System Tables Data Dictionary « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. System Tables Data Dictionary
3. dba_extents

SQL>
SQL> COLUMN    segment_name FORMAT a15
SQL> SELECT    segment_name, segment_type, COUNT(*), SUM(bytes)
  2  FROM      dba_extents
  3  WHERE     segment_name IN
  4            ('COL$', 'DEPENDENCY$', 'ERROR$', 'IDL_CHAR$',
  5             'IDL_SB4$', 'IDL_UB1$', 'IDL_UB2$', 'LINK$', 'OBJ$',
  6             'OBJAUTH$', 'SOURCE$', 'SYSAUTH$', 'TRIGGER$',
  7             'TRIGGERCOL$', 'USER$')
  8             and rownum < 50
  9  GROUP BY  segment_name, segment_type
 10  ORDER BY  segment_type, segment_name;

SEGMENT_NAME    SEGMENT_TYPE         COUNT(*) SUM(BYTES)
--------------- ------------------ ---------- ----------
OBJ$            TABLE                      17    2097152
OBJAUTH$        TABLE                       2     131072
SOURCE$         TABLE                      30   15728640

SQL>
SQL>