Script:以下脚本可以用于诊断segement space usage问题：

set serveroutput on;

      declare
        v_unformatted_blocks number;
        v_unformatted_bytes number;
        v_fs1_blocks number;
        v_fs1_bytes number;
        v_fs2_blocks number;
        v_fs2_bytes number;
        v_fs3_blocks number;
        v_fs3_bytes number;
       v_fs4_blocks number;
       v_fs4_bytes number;
       v_full_blocks number;
       v_full_bytes number;
     begin
     dbms_space.space_usage ('&OWNER', '&TABNAME', 'TABLE', v_unformatted_blocks,
     v_unformatted_bytes, v_fs1_blocks, v_fs1_bytes, v_fs2_blocks, v_fs2_bytes,
     v_fs3_blocks, v_fs3_bytes, v_fs4_blocks, v_fs4_bytes, v_full_blocks, v_full_bytes);
     dbms_output.put_line('Unformatted Blocks = '||v_unformatted_blocks);
     dbms_output.put_line('FS1 Blocks              = '||v_fs1_blocks);
     dbms_output.put_line('FS2 Blocks              = '||v_fs2_blocks);
     dbms_output.put_line('FS3 Blocks              = '||v_fs3_blocks);
     dbms_output.put_line('FS4 Blocks              = '||v_fs4_blocks);
     dbms_output.put_line('Full Blocks              = '||v_full_blocks);
     end;
     / 

SELECT TABLE_NAME ,  (BLOCKS *8192 / 1024/1024 ) - (NUM_ROWS*AVG_ROW_LEN/1024/1024)
"Data lower than HWM in MB"   FROM  DBA_TABLES WHERE  UPPER(owner) =UPPER('&OWNER') order by 2 desc;

 select tablespace_name, allocated_space, reclaimable_space from table(dbms_space.asa_recommendations('TRUE', 'TRUE', 'ALL'))