UNDO 表領域の使用率

計算式は UNDO 表領域の使用率 = (ACTIVE + UNEXPIRED のエクステントサイズ) / UNDO 表領域全体のサイズ です。

以下のSQLで確認できます。

select to_char(sysdate,'YYYY/MM/DD HH24:MI:SS') "TIME",
       round("USED_SIZE(MB)", 3) "USED(MB)",
       round("TBS_SIZE(MB)", 3)  "TBS(MB)",
       round("USED_SIZE(MB)"/"TBS_SIZE(MB)" * 100, 3) "USAGE(%)"
  from (select sum(BYTES)/1024/1024 "USED_SIZE(MB)"
          from DBA_UNDO_EXTENTS
         where STATUS in ('ACTIVE', 'UNEXPIRED')
           and TABLESPACE_NAME = 'UNDOTBS1') ,
       (select sum(BYTES)/1024/1024 "TBS_SIZE(MB)"
          from DBA_DATA_FILES
         where TABLESPACE_NAME = 'UNDOTBS1') ;