FW:Oracle之七零八落

SELECT INSTR(‘AAAC‘, ‘AAC‘) FROM DUAL; --2
SELECT SUBSTR(‘ABC‘, 2, 1) FROM DUAL; --B
SELECT ‘AA‘ || CHR(ASCII(‘B‘) + 1) FROM DUAL; -- AAC

SELECT * FROM V$VERSION;
SELECT * FROM PRODUCT_COMPONENT_VERSION;

-- 查询表空间
SELECT UPPER(F.TABLESPACE_NAME) "表空间名",
       D.TOT_GROOTTE_MB "表空间大小(M)",
       D.TOT_GROOTTE_MB - F.TOTAL_BYTES "已使用空间(M)",
       TO_CHAR(ROUND((D.TOT_GROOTTE_MB - F.TOTAL_BYTES) / D.TOT_GROOTTE_MB * 100,
                     2),
               ‘990.99‘) "使用比",
       F.TOTAL_BYTES "空闲空间(M)",
       F.MAX_BYTES "最大块(M)"
  FROM (SELECT TABLESPACE_NAME,
               ROUND(SUM(BYTES) / (1024 * 1024), 2) TOTAL_BYTES,
               ROUND(MAX(BYTES) / (1024 * 1024), 2) MAX_BYTES
          FROM SYS.DBA_FREE_SPACE
         GROUP BY TABLESPACE_NAME) F,
       (SELECT DD.TABLESPACE_NAME,
               ROUND(SUM(DD.BYTES) / (1024 * 1024), 2) TOT_GROOTTE_MB
          FROM SYS.DBA_DATA_FILES DD
         GROUP BY DD.TABLESPACE_NAME) D
 WHERE D.TABLESPACE_NAME = F.TABLESPACE_NAME
 ORDER BY 4 DESC;

当误删除某些表时，可以通过命令恢复回来：
flashback table tablename to befor drop；
 
查看是否开启了闪回功能：
select flashback_on from v$database;
 
如果确定某些表确实可以删除，可以使用下面的语句，就不会出现BIN$开头的表了
drop table table_name purge;
 
删除Bin开头的表,即已经drop但存在于回收站中的表：
查询所有此类表SQL> select * from recyclebin where type=‘TABLE‘;
用来删除回收站中所有的表SQL> PURGE RECYCLEBIN;
用来删除指定的表SQL> PURGE TABLE TABLE_NAME;
可以在的Drop表时不产生Bin型表SQL> DROP TABLE "TableName" purge;

-- 查询数据库被锁住的进程
SELECT A.SID, B.OWNER, OBJECT_NAME, OBJECT_TYPE
  FROM V$LOCK A, ALL_OBJECTS B
 WHERE TYPE = ‘TM‘
   AND A.ID1 = B.OBJECT_ID;

SELECT SID, SERIAL# FROM V$SESSION WHERE SID = &SID;

ALTER SYSTEM KILL SESSION ‘SID, SERIAL#’;

SELECT SID, SERIAL#
  FROM V$SESSION
 WHERE SID IN (SELECT A.SID
                 FROM V$LOCK A, ALL_OBJECTS B
                WHERE TYPE = ‘TM‘
                  AND A.ID1 = B.OBJECT_ID);

-- 查询/删除重复记录
DELETE FROM EMP E
 WHERE E.ROWID > (SELECT MIN(X.ROWID) FROM EMP X WHERE X.EMP_NO = E.EMP_NO);

SELECT *
  FROM COM_ITEM_CODE E
 WHERE E.ROWID >
       (SELECT MIN(X.ROWID) FROM COM_ITEM_CODE X WHERE X.BILL_NO = E.BILL_NO);

-- 反向递归
SELECT H.HR_DEPT_CODE, H.ERP_DEPT_NAME, H.ERP_DEPT_CODE, H.ERP_DEPT_NAME
  FROM (SELECT *
          FROM AOL_SYS_ORGANIZATION
         START WITH ORG_NO = ‘00164‘
        CONNECT BY PARENT_ORG_ID = PRIOR LINE_ID) O,
       AOL_COM_HRTOERP H
 WHERE O.ORG_NO = H.HR_DEPT_CODE;

-- 1、查看表所占空间
SELECT TABLESPACE_NAME,
       TO_CHAR(SUM(BYTES) / (1024 * 1024), ‘999G999D999‘) CNT_MB
  FROM DBA_EXTENTS
 WHERE OWNER = ‘&OWNER‘
   AND SEGMENT_NAME = ‘&TABLE_NAME‘
   AND SEGMENT_TYPE LIKE ‘TABLE%‘ * /
 GROUP BY TABLESPACE_NAME;

--有两种含义的表大小。--一种是分配给一个表的物理空间数量，而不管空间是否被使用。可以这样查询获得字节数：

SELECT SEGMENT_NAME, BYTES FROM USER_SEGMENTS WHERE SEGMENT_TYPE = ‘TABLE‘;

SELECT SEGMENT_NAME, SUM(BYTES) / 1024 / 1024
  FROM USER_EXTENTS
 GROUP BY SEGMENT_NAME;

-- 另一种表实际使用的空间。这样查询：

ANALYZE TABLE ABCDEF COMPUTE STATISTICS;
SELECT NUM_ROWS * AVG_ROW_LEN FROM USER_TABLES WHERE TABLE_NAME = ‘ABCDEF‘;

SELECT NUM_ROWS, TABLE_NAME FROM USER_TABLES;

-- 存储过程的闪回
SQL> set pagesize 0
SQL> column text format a4000
SQL> spool C:\7.text
Started spooling to C:\7.text
SQL> SELECT text
       FROM DBA_source AS OF TIMESTAMP TO_TIMESTAMP(‘2009-12-25 10:07:00‘, ‘YYYY-MM-DD HH24:MI:SS‘)
      WHERE OWNER = ‘用户名‘
        AND NAME = ‘存储过程名’
       ORDER BY LINE
     ;
SQL> spool off;

-- 修改DBLINK的global_name
update global_name set global_name=‘oradb‘;