在Oracle的11g版本中提供了统计数据自动收集的功能。在部署安装11g Oracle软件过程中，其中有一个步骤便是提示是否启动这个功能(默认是启用这个功能)。
1、查看自动收集统计信息的任务及状态：
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、禁止自动收集统计信息的任务
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、启用自动收集统计信息的任务
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、获得当前自动收集统计信息的执行时间：
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：任务名 REPEAT_INTERVAL：任务重复间隔时间 DURATION：持续时间
5.修改统计信息执行的时间：
1.停止任务：
SQL> BEGIN
2 DBMS_SCHEDULER.DISABLE(
3 name => '"SYS"."THURSDAY_WINDOW"',
4 force => TRUE); --停止任务是true
5 END;
6 / SQL> 2.修改任务的持续时间，单位是分钟：
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.开始执行时间，BYHOUR=2，表示2点开始执行：
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.开启任务：
SQL> BEGIN
2 DBMS_SCHEDULER.ENABLE(
3 name => '"SYS"."THURSDAY_WINDOW"');
4 END;
5 /
SQL> 5.查看修改后的情况：
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.查看统计信息执行的历史记录
--维护窗口组
select * from dba_scheduler_window_groups;
--维护窗口组对应窗口
select * from dba_scheduler_wingroup_members
--维护窗口历史信息
select* from dba_scheduler_windows --查询自动收集任务正在执行的job
select * from DBA_AUTOTASK_CLIENT_JOB;
--查询自动收集任务历史执行状态
select * from DBA_AUTOTASK_JOB_HISTORY;
select * from DBA_AUTOTASK_CLIENT_HISTORY;
--整理自网络