Oracle 11g 之自動收集統計信息

　　在Oracle的11g版本中提供了統計數據自動收集的功能。在部署安裝11g Oracle軟件過程中，其中有一個步驟便是提示是否啟動這個功能(默認是啟用這個功能)。

1、查看自動收集統計信息的任務及狀態：

SQL> select client_name,status from dba_autotask_client;

CLIENT_NAME                                                      STATUS
---------------------------------------------------------------- --------
auto optimizer stats collection                                  ENABLED
auto space advisor                                               ENABLED
sql tuning advisor                                               DISABLED

SQL> 

2、禁止自動收集統計信息的任務

SQL> exec DBMS_AUTO_TASK_ADMIN.DISABLE(client_name => 'auto optimizer stats collection',operation => NULL,window_name => NULL);

PL/SQL procedure successfully completed.

SQL> select client_name,status from dba_autotask_client;

CLIENT_NAME                                                      STATUS
---------------------------------------------------------------- --------
auto optimizer stats collection                                  DISABLED
auto space advisor                                               ENABLED
sql tuning advisor                                               DISABLED

SQL> 

3、啟用自動收集統計信息的任務

SQL> exec DBMS_AUTO_TASK_ADMIN.ENABLE(client_name => 'auto optimizer stats collection',operation => NULL,window_name => NULL);

PL/SQL procedure successfully completed.

SQL> select client_name,status from dba_autotask_client;

CLIENT_NAME                                                      STATUS
---------------------------------------------------------------- --------
auto optimizer stats collection                                  ENABLED
auto space advisor                                               ENABLED
sql tuning advisor                                               DISABLED

SQL>

4、獲得當前自動收集統計信息的執行時間：

SQL> col  WINDOW_NAME format a20
SQL> col REPEAT_INTERVAL format a70
SQL> col DURATION format a20
SQL> set line 180
SQL> select t1.window_name,t1.repeat_interval,t1.duration 
  2  from dba_scheduler_windows t1,dba_scheduler_wingroup_members t2
  3  where t1.window_name=t2.window_name and t2.window_group_name in ('MAINTENANCE_WINDOW_GROUP','BSLN_MAINTAIN_STATS_SCHED');

WINDOW_NAME          REPEAT_INTERVAL                                                        DURATION
-------------------- ---------------------------------------------------------------------- --------------------
WEDNESDAY_WINDOW     freq=daily;byday=WED;byhour=22;byminute=0; bysecond=0                  +000 04:00:00
SATURDAY_WINDOW      freq=daily;byday=SAT;byhour=6;byminute=0; bysecond=0                   +000 20:00:00
THURSDAY_WINDOW      freq=daily;byday=THU;byhour=22;byminute=0; bysecond=0                  +000 04:00:00
TUESDAY_WINDOW       freq=daily;byday=TUE;byhour=22;byminute=0; bysecond=0                  +000 04:00:00
SUNDAY_WINDOW        freq=daily;byday=SUN;byhour=6;byminute=0; bysecond=0                   +000 20:00:00
MONDAY_WINDOW        freq=daily;byday=MON;byhour=22;byminute=0; bysecond=0                  +000 04:00:00
FRIDAY_WINDOW        freq=daily;byday=FRI;byhour=22;byminute=0; bysecond=0                  +000 04:00:00

7 rows selected.

SQL>

其中：WINDOW_NAME：任務名       REPEAT_INTERVAL：任務重復間隔時間      DURATION：持續時間

5.修改統計信息執行的時間：

1.停止任務：
SQL> BEGIN
  2    DBMS_SCHEDULER.DISABLE(
  3    name => '"SYS"."THURSDAY_WINDOW"',
  4    force => TRUE);  --停止任務是true
  5  END;
  6  /

SQL>


2.修改任務的持續時間，單位是分鍾：
SQL> BEGIN
  2    DBMS_SCHEDULER.SET_ATTRIBUTE(
  3    name => '"SYS"."THURSDAY_WINDOW"',
  4    attribute => 'DURATION',
  5    value => numtodsinterval(60,'minute'));
  6  END;
  7  /
SQL>

3.開始執行時間，BYHOUR=2，表示2點開始執行：
SQL> BEGIN
  2    DBMS_SCHEDULER.SET_ATTRIBUTE(
  3    name => '"SYS"."THURSDAY_WINDOW"',
  4    attribute => 'REPEAT_INTERVAL',
  5    value => 'freq=daily;byday=THU;byhour=10;byminute=40;bysecond=0');
  6  END;
  7  /

SQL> 


4.開啟任務：
SQL> BEGIN
  2    DBMS_SCHEDULER.ENABLE(
  3    name => '"SYS"."THURSDAY_WINDOW"');
  4  END;
  5  /
SQL> 



5.查看修改后的情況：
SQL> select t1.window_name,t1.repeat_interval,t1.duration 
  2  from dba_scheduler_windows t1,dba_scheduler_wingroup_members t2
  3  where t1.window_name=t2.window_name and t2.window_group_name in ('MAINTENANCE_WINDOW_GROUP','BSLN_MAINTAIN_STATS_SCHED');

WINDOW_NAME          REPEAT_INTERVAL                                                        DURATION
-------------------- ---------------------------------------------------------------------- --------------------
WEDNESDAY_WINDOW     freq=daily;byday=WED;byhour=22;byminute=0; bysecond=0                  +000 04:00:00
SATURDAY_WINDOW      freq=daily;byday=SAT;byhour=6;byminute=0; bysecond=0                   +000 20:00:00
THURSDAY_WINDOW      freq=daily;byday=THU;byhour=10;byminute=40;bysecond=0                  +000 01:00:00
TUESDAY_WINDOW       freq=daily;byday=TUE;byhour=22;byminute=0; bysecond=0                  +000 04:00:00
SUNDAY_WINDOW        freq=daily;byday=SUN;byhour=6;byminute=0; bysecond=0                   +000 20:00:00
MONDAY_WINDOW        freq=daily;byday=MON;byhour=22;byminute=0; bysecond=0                  +000 04:00:00
FRIDAY_WINDOW        freq=daily;byday=FRI;byhour=22;byminute=0; bysecond=0                  +000 04:00:00

SQL> 

6.查看統計信息執行的歷史記錄

--維護窗口組
select * from dba_scheduler_window_groups;
--維護窗口組對應窗口
select * from dba_scheduler_wingroup_members
--維護窗口歷史信息
select* from dba_scheduler_windows

--查詢自動收集任務正在執行的job 
select * from DBA_AUTOTASK_CLIENT_JOB;
--查詢自動收集任務歷史執行狀態
select * from DBA_AUTOTASK_JOB_HISTORY;
select * from DBA_AUTOTASK_CLIENT_HISTORY; 

 

--整理自網絡