Hi all,

Please see the folllowing test:

Code:
SQL> set linesize 10000
SQL> spool c:\temp\hwm.txt
SQL> set timing on
SQL> select count(*) from TEST;

  COUNT(*)
----------
   2798098

Elapsed: 00:08:24.01

SQL> SELECT tablespace_name "Tablespace Name",  
  2  bytes/1048576 "Size(M)" 
  3  FROM dba_segments
  4  where owner='TEST';

Tablespace Name                                                                               Size(M
------------------------------------------------------------------------------------------ ---------
TEST_DATA                                                                                       145.5
TEST_DATA                                                                                        48.5
TEST_DATA                                                                                        56.5

Elapsed: 00:00:01.04

SQL> delete from TEST;

2798098 rows deleted.

SQL> ALTER TABLE TEST.TEST MOVE 
  2  /

Table altered.

Elapsed: 00:00:13.03
SQL> ALTER INDEX TEST.TEST REBUILD LOGGING NOREVERSE TABLESPACE TEST_DATA
  2  /

Index altered.


Elapsed: 00:00:00.02
SQL> ALTER INDEX TEST.TEST_PK REBUILD LOGGING NOREVERSE TABLESPACE TEST_DATA
  2  /

Index altered.

Elapsed: 00:00:00.04
SQL> SELECT tablespace_name "Tablespace Name",  
  2  bytes/1048576 "Size(M)" 
  3  FROM dba_segments
  4  where owner='TEST';

Tablespace Name                                                                               Size(M
------------------------------------------------------------------------------------------ ---------
TEST_DATA                                                                                       100.5
TEST_DATA                                                                                        48.5
TEST_DATA                                                                                        56.5

Elapsed: 00:00:00.06
SQL> SPOOL OFF
SQL>
Why HWM is not shrink close to zero after I move tables and rebuild index???? I intentionally move it on the same tablespace, I also tried to move to different tablespace but it doens't help.

could someone please tell me why???