10gR2
需要將一個普通錶轉為按月分割槽提高查詢效率

測試如下：

一、建立測試表

SQL> CREATE TABLE T(ID NUMBER ,TIME DATE);

Table created.

SQL> DESC T;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 ID                                                 NUMBER
 TIME                                               DATE


SQL> INSERT INTO T SELECT ROWNUM,CREATED FROM ALL_OBJECTS;
rows created.

SQL> SET TIMING ON
SQL> select count(*) from t;

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

二、測試表是否可以線上重定義

SQL> EXEC DBMS_REDEFINITION.CAN_REDEF_TABLE('test','T', DBMS_REDEFINITION.CONS_USE_PK);
BEGIN DBMS_REDEFINITION.CAN_REDEF_TABLE('test','T', DBMS_REDEFINITION.CONS_USE_PK); END;

                                                    *
ERROR at line 1:
ORA-06550: line 1, column 53:
PLS-00201: identifier 'DBMS_REDEFINITION' must be declared
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored
 

出錯原因是沒有賦予‘DBMS_REDEFINITION' 的執行許可權。解決的辦法是：

dba使用者授予許可權

SQL> GRANT ALL ON SYS.DBMS_REDEFINITION TO TEST;

Grant succeeded.


SQL>  GRANT CREATE ANY TABLE, ALTER ANY TABLE, DROP ANY TABLE, LOCK ANY TABLE, SELECT ANY TABLE TO TEST;

Grant succeeded.

回到test使用者繼續驗證

SQL> EXEC DBMS_REDEFINITION.CAN_REDEF_TABLE('test', 'T', DBMS_REDEFINITION.CONS_USE_PK);
BEGIN DBMS_REDEFINITION.CAN_REDEF_TABLE('test', 'T', DBMS_REDEFINITION.CONS_USE_PK); END;

*
ERROR at line 1:
ORA-12089: cannot online redefine table "test"."T" with no primary key
ORA-06512: at "SYS.DBMS_REDEFINITION", line 137
ORA-06512: at "SYS.DBMS_REDEFINITION", line 1479
ORA-06512: at line 1
 

如果沒有定義主鍵會提示以上錯誤資訊

建立主鍵：

SQL> alter table t add constraint pk_t primary key(id);

Table altered.

再次驗證成功

SQL> EXEC DBMS_REDEFINITION.CAN_REDEF_TABLE('test','T',DBMS_REDEFINITION.CONS_USE_PK);

PL/SQL procedure successfully completed.

三、建立中間表及分割槽

SQL> select to_char(min(time),'YYYY-MM-DD HH24:MI:SS') from t;

TO_CHAR(MIN(TIME),'
-------------------
2003-06-13 21:11:01

SQL> select to_char(max(time),'YYYY-MM-DD HH24:MI:SS') from t;

TO_CHAR(MAX(TIME),'
-------------------
2013-05-07 21:40:35

SQL> CREATE TABLE T_NEW (ID NUMBER PRIMARY KEY, TIME DATE) PARTITION BY RANGE (TIME)
      (PARTITION T_2003 VALUES LESS THAN (TO_DATE('2004-1-1', 'YYYY-MM-DD')),
      PARTITION T_2004 VALUES LESS THAN (TO_DATE('2005-1-1', 'YYYY-MM-DD')),
      PARTITION T_2005 VALUES LESS THAN (TO_DATE('2006-1-1', 'YYYY-MM-DD')),
      PARTITION T_2006 VALUES LESS THAN (TO_DATE('2007-1-1', 'YYYY-MM-DD')),  
      PARTITION T_2007 VALUES LESS THAN (TO_DATE('2008-1-1', 'YYYY-MM-DD')),
     PARTITION T_2008 VALUES LESS THAN (TO_DATE('2009-1-1', 'YYYY-MM-DD')),
     PARTITION T_2009 VALUES LESS THAN (TO_DATE('2010-1-1', 'YYYY-MM-DD')),
     PARTITION T_2010 VALUES LESS THAN (TO_DATE('2011-1-1', 'YYYY-MM-DD')),
     PARTITION T_2011 VALUES LESS THAN (TO_DATE('2012-1-1', 'YYYY-MM-DD')),
     PARTITION T_2012 VALUES LESS THAN (TO_DATE('2013-1-1', 'YYYY-MM-DD')),
     PARTITION T_2013 VALUES LESS THAN (TO_DATE('2014-1-1', 'YYYY-MM-DD')));

四、線上重新定義操作

SQL> exec dbms_redefinition.start_redef_table('TEST','T','T_NEW');

PL/SQL procedure successfully completed.

一些問題：

建立過程關於物化檢視的問題

SQL> desc user_mviews;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 OWNER                                     NOT NULL VARCHAR2(30)
 MVIEW_NAME                                NOT NULL VARCHAR2(30)
 CONTAINER_NAME                            NOT NULL VARCHAR2(30)
....省略

SQL> select mview_name from user_mviews;

no rows selected

SQL> EXEC DBMS_REDEFINITION.START_REDEF_TABLE('test','T','T_NEW');

PL/SQL procedure successfully completed.

SQL>  select mview_name from user_mviews;

MVIEW_NAME
------------------------------
T_NEW

SQL>

#start後會產生一個物化檢視，如果中途失敗不做abort會導致物化檢視一次存在，下一次操作時會報：

SQL> EXEC DBMS_REDEFINITION.START_REDEF_TABLE('test', 'T', 'T_NEW');                        
BEGIN DBMS_REDEFINITION.START_REDEF_TABLE('test', 'T', 'T_NEW'); END;        

*
ERROR at line 1:
ORA-12091: cannot online redefine table "test"."T" with
materialized views
ORA-06512: at "SYS.DBMS_REDEFINITION", line 50
ORA-06512: at "SYS.DBMS_REDEFINITION", line 1343
ORA-06512: at line 1

SQL> drop materialized view log on T;

ORA-14400: inserted partition key does not map to any partition

這個報錯的意思是分割槽表建立時有值在分割槽表之外，未被包含，可以查詢下資料把缺失的分割槽表建立起來
參考：

SQL> select to_char(max(time),'YYYY-MM-DD HH24:MI:SS') from t;

TO_CHAR(MAX(TIME),'
-------------------
2014-05-01 21:40:35  

SQL> select partition_name from user_tab_partitions where table_name='T_NEW';

PARTITION_NAME
------------------------------
T_2003
T_2004
T_2005
T_2006
T_2007
T_2008
T_2009
T_2010
T_2011
T_2012
T_2013
rows selected.

SQL> ALTER TABLE T_NEW ADD PARTITION T_2014 VALUES LESS THAN (TO_DATE('2015-01-01','YYYY-MM-DD'));

Table altered.


SQL> select partition_name from user_tab_partitions where table_name='T_NEW';

PARTITION_NAME
------------------------------
T_2003
T_2004
T_2005
T_2006
T_2007
T_2008
T_2009
T_2010
T_2011
T_2012
T_2013
T_2014
rows selected.

五、執行重定義後的分割槽資料同步

SQL>  exec dbms_redefinition.sync_interim_table('TEST','T','T_NEW');

PL/SQL procedure successfully completed.

六、完成線上重定義操作

SQL>  EXEC DBMS_REDEFINITION.FINISH_REDEF_TABLE('TEST','T','T_NEW');

PL/SQL procedure successfully completed.

如果執行線上重定義的過程中出錯

可以在執行dbms_redefinition.start_redef_table之後到執行dbms_redefinition.finish_redef_table之前的時間裡
執行：DBMS_REDEFINITION.abort_redef_table('test', 't', 't_new')以放棄執行線上重定義。

By cycsa http://www.cnblogs.com/cycsa

轉載自-----https://www.cnblogs.com/cycsa/archive/2013/05/08/3067222.html