Oracle釋放高水位線

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/*****************************************************************
原因：由於原匯出資料庫沒有整理資料表空間其中主要包括兩方面，
一是使用者產生太多的DELETE，致使表的高位線（HWM）在很高的位置，
所以儘管資料量很小，但是佔據的資料表空間很大，二是索引沒有重建，
頻繁的刪除以及更新使得索引越來越大，REBUILD索引是個很必要的事情
*****************************************************************/

--** 優先處理CUX客制化對象

--Step1
--Tablespace Summary
  SELECT A.TABLESPACE_NAME,
         A.TOTAL M_TOTAL,
         NVL (B.USED, 0) M_USED,
         NVL ( (B.USED / A.TOTAL) * 100, 0) PCT_USED,
         A.FILE_NAME
    FROM (  SELECT TABLESPACE_NAME,
                   SUM (BYTES) / (1024 * 1024) TOTAL,
                   WMSYS.WM_CONCAT (FILE_NAME) FILE_NAME
              FROM SYS.DBA_DATA_FILES
          GROUP BY TABLESPACE_NAME) A,
         (SELECT TABLESPACE_NAME, BYTES / (1024 * 1024) USED
            FROM SYS.SM$TS_USED) B
   WHERE A.TABLESPACE_NAME = B.TABLESPACE_NAME(+)
   --AND A.TABLESPACE_NAME LIKE ‘CUX%‘
ORDER BY NVL ( (B.USED / A.TOTAL) * 100, 0) DESC;

--Tablespace Objects Detail
  SELECT A.TABLESPACE_NAME,
         A.TOTAL M_TOTAL,
         NVL (B.USED, 0) M_USED,
         NVL ( (B.USED / A.TOTAL) * 100, 0) PCT_USED,
         A.FILE_NAME,
         C.OJBECT_TYPE,
         C.OJBECT_NAME,
         C.M_OBJ_USED,
         NVL ( (C.M_OBJ_USED / A.TOTAL) * 100, 0) PCT_OBJ_USED
    FROM (  SELECT TABLESPACE_NAME,
                   SUM (BYTES) / (1024 * 1024) TOTAL,
                   WMSYS.WM_CONCAT (FILE_NAME) FILE_NAME
              FROM SYS.DBA_DATA_FILES
          GROUP BY TABLESPACE_NAME) A,
         (SELECT TABLESPACE_NAME, BYTES / (1024 * 1024) USED
            FROM SYS.SM$TS_USED) B,
         (SELECT TABLESPACE_NAME,
                 SEGMENT_NAME OJBECT_NAME,
                 SEGMENT_TYPE OJBECT_TYPE,
                 (BYTES / 1024 / 1024) M_OBJ_USED
            FROM DBA_SEGMENTS
           WHERE SEGMENT_TYPE IN (‘TABLE‘, ‘INDEX‘)) C
   WHERE     A.TABLESPACE_NAME = B.TABLESPACE_NAME(+)
         AND A.TABLESPACE_NAME = C.TABLESPACE_NAME(+)
ORDER BY NVL ( (B.USED / A.TOTAL) * 100, 0) DESC;

--Step2
-------------------------------------
--釋放高水位線 HWM
--只對有清理過資料的表對象執行（耗時過長）
DECLARE
   L_SQL1        VARCHAR2 (1000);
   L_SQL2        VARCHAR2 (1000);
BEGIN
   FOR R IN (SELECT (OWNER || ‘.‘ || SEGMENT_NAME) OBJ
               FROM DBA_SEGMENTS
              WHERE SEGMENT_TYPE = ‘TABLE‘ AND TABLESPACE_NAME LIKE ‘CUX%‘
              AND SEGMENT_NAME IN(‘CUX_INV_ISSUE_OA_LOG‘))
   LOOP
      L_SQL1 := ‘alter table ‘ || R.OBJ || ‘ enable row movement‘;
      L_SQL2 := ‘alter table ‘ || R.OBJ || ‘ shrink space‘;
      DBMS_OUTPUT.PUT_LINE (R.OBJ);

      EXECUTE IMMEDIATE L_SQL1;
      EXECUTE IMMEDIATE L_SQL2;
   END LOOP;
END;

-------------------------------
/*
--暫不應用
--Rebuild Index
DECLARE
   L_SQL   VARCHAR2 (1000);
BEGIN
   FOR R IN (SELECT (OWNER||‘.‘||SEGMENT_NAME) OBJ
               FROM DBA_SEGMENTS
              WHERE SEGMENT_TYPE = ‘INDEX‘ AND TABLESPACE_NAME = ‘CUX_INDEX‘)
   LOOP
      L_SQL := ‘alter index ‘ || R.OBJ || ‘ rebuild online‘;
      DBMS_OUTPUT.PUT_LINE (L_SQL);

      EXECUTE IMMEDIATE L_SQL;
   END LOOP;
END;
*/

--刪除表同時刪除資源回收筒 Shift+Delete
--DROP TABLE CUX.CUX_INV_ISSUE_OA_LOG_TEST1 PURGE;
--alter database datafile ‘filename‘ resize size;

Oracle釋放高水位線