Oracle 11g 之自动收集统计信息
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
