Oracle数据库里提供了自动维护任务，以保证Oracle数据库可以更高效的运行。在不同的Oracle版本中，自动任务的种类和执行方式也有区别。本文以10g和11g为主来认识Oracle里的自动任务。
1、种类
10g里的自动任务有两种：
- AUTO_SPACE_ADVISOR_JOB，自动空间顾问JOB
- GATHER_STATS_JOB，自动收集统计信息JOB
11g里的自动任务有三种：
- auto optimizer stats collection，自动统计信息收集顾问
- auto space advisor，自动空间顾问
- sql tuning advisor，sql调优顾问
2、实现方式
10g里的自动任务是以SCHEDULER的JOB形式运行的，可以在dba_scheduler_jobs视图里查到相关的JOB。
SQL> set linesize 200 SQL> col owner for a30 SQL> col job_name for a30 SQL> select owner,job_name from dba_scheduler_jobs where job_class=‘AUTO_TASKS_JOB_CLASS‘; OWNER JOB_NAME ------------------------------ ------------------------------ SYS AUTO_SPACE_ADVISOR_JOB SYS GATHER_STATS_JOB
11g里的自动任务使用的是11g的新特性AUTOTASK的方式实现的。可以从dba_autotask_client视图中查到相关信息。
[email protected]>SELECT client_name,status FROM dba_autotask_client; CLIENT_NAME STATUS ---------------------------------------- ------------------------ auto optimizer stats collection ENABLED auto space advisor ENABLED sql tuning advisor ENABLED
3、维护窗口时间
两个版本中自动任务的执行时间是不同的。
10g中分为两个时间段WEEKNIGHT_WINDOW和WEEKEND_WINDOW，可以从dba_scheduler_windows视图中查到。它们分别的运行开始时间和持续时间为：
WEEKNIGHT_WINDOW，每周一至周五晚22:00:00开始，持续8小时
WEEKEND_WINDOW，第周六00:00:00，持续2天
11g中维护窗口分得更细，分为7个，即第一天个维护窗口，可以针对不同的需求做出更细粒度的调整，dba_scheduler_windows视图中查到，分别为MONDAY_WINDOW,TUESDAY_WINDOW,WEDNESDAY_WINDOW,THURSDAY_WINDOW,FRIDAY_WINDOW,SATURDAY_WINDOW,SUNDAY_WINDOW。开始时间和持续时间分别为：
周一到周五晚22:00:00开始，持续4小时，周六和周日早6:00:00开始，执行20小时。
4、维护方式
由于10g和11g中实现方式的不同，维护方式自然就不一样了。
10g的维护方式与普通的SCHEDULER的JOB一样。
--停用JOB SQL> exec dbms_scheduler.disable(‘AUTO_SPACE_ADVISOR_JOB‘); PL/SQL procedure successfully completed. SQL> select enabled from dba_scheduler_jobs where job_name=‘AUTO_SPACE_ADVISOR_JOB‘; ENABLED --------------- FALSE --启用JOB SQL> exec dbms_scheduler.ENABLE(‘AUTO_SPACE_ADVISOR_JOB‘); PL/SQL procedure successfully completed. SQL> select enabled from dba_scheduler_jobs where job_name=‘AUTO_SPACE_ADVISOR_JOB‘; ENABLED --------------- TRUE
下面重点介绍11g里自动任务的维护。
1)停用和启用自动维护任务
--停用sql tuning advisor [email protected]>BEGIN 2 dbms_auto_task_admin.disable( 3 client_name => ‘sql tuning advisor‘, 4 operation => NULL, 5 window_name => NULL); 6 END; 7 / PL/SQL procedure successfully completed. [email protected]>select client_name,status from dba_autotask_client; CLIENT_NAME STATUS ---------------------------------------- ------------------------ auto optimizer stats collection ENABLED auto space advisor ENABLED sql tuning advisor DISABLED --启用sql tuning advisor [email protected]>BEGIN 2 dbms_auto_task_admin.enable( 3 client_name => ‘sql tuning advisor‘, 4 operation => NULL, 5 window_name => NULL); 6 END; 7 / PL/SQL procedure successfully completed. [email protected]>select client_name,status from dba_autotask_client; CLIENT_NAME STATUS ---------------------------------------- ------------------------ auto optimizer stats collection ENABLED auto space advisor ENABLED sql tuning advisor ENABLED --停用所有维护窗口下的所有的自动任务 [email protected]>exec dbms_auto_task_admin.disable; PL/SQL procedure successfully completed. [email protected]>select window_name,autotask_status from dba_autotask_window_clients; WINDOW_NAME AUTOTASK_STATUS ------------------------------ ------------------------ MONDAY_WINDOW DISABLED TUESDAY_WINDOW DISABLED WEDNESDAY_WINDOW DISABLED THURSDAY_WINDOW DISABLED FRIDAY_WINDOW DISABLED SATURDAY_WINDOW DISABLED SUNDAY_WINDOW DISABLED 7 rows selected. --启用所有维护窗口下的所有自动任务 [email protected]>exec dbms_auto_task_admin.enable; PL/SQL procedure successfully completed. [email protected]>select window_name,autotask_status from dba_autotask_window_clients; WINDOW_NAME AUTOTASK_STATUS ------------------------------ ------------------------ WEDNESDAY_WINDOW ENABLED FRIDAY_WINDOW ENABLED SATURDAY_WINDOW ENABLED THURSDAY_WINDOW ENABLED TUESDAY_WINDOW ENABLED SUNDAY_WINDOW ENABLED MONDAY_WINDOW ENABLED 7 rows selected. --停用针对某个维护窗口的自动任务 [email protected]>BEGIN 2 dbms_auto_task_admin.disable( 3 client_name => ‘sql tuning advisor‘, 4 operation => NULL, 5 window_name => ‘MONDAY_WINDOW‘); 6 END; 7 / PL/SQL procedure successfully completed. [email protected]>select window_name,autotask_status,sql_tune_advisor from dba_autotask_window_clients; WINDOW_NAME AUTOTASK_STATUS SQL_TUNE_ADVISOR ------------------------------ ------------------------ ------------------------ MONDAY_WINDOW ENABLED DISABLED TUESDAY_WINDOW ENABLED ENABLED WEDNESDAY_WINDOW ENABLED ENABLED THURSDAY_WINDOW ENABLED ENABLED FRIDAY_WINDOW ENABLED ENABLED SATURDAY_WINDOW ENABLED ENABLED SUNDAY_WINDOW ENABLED ENABLED 7 rows selected.
2、配置维护窗口
这个与10g的类似，都是使用dbms_scheduler包来操作
--修改维护窗口的属性，把SATURDAY_WINDOW的持续时间修改为4小时 [email protected]>BEGIN 2 dbms_scheduler.disable( 3 name => ‘SATURDAY_WINDOW‘); 4 dbms_scheduler.set_attribute( 5 name => ‘SATURDAY_WINDOW‘, 6 attribute => ‘DURATION‘, 7 value => numtodsinterval(4, ‘hour‘)); 8 dbms_scheduler.enable( 9 name => ‘SATURDAY_WINDOW‘); 10 END; 11 / PL/SQL procedure successfully completed. [email protected]>SELECT duration FROM dba_scheduler_windows WHERE window_name=‘SATURDAY_WINDOW‘; DURATION --------------------------------------------------------------------------- +000 04:00:00
11g自动维护任务参考官方文档：http://docs.oracle.com/cd/E11882_01/server.112/e25494/tasks.htm#ADMIN12344
时间： 2024-10-20 10:43:30