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Oracle 11g 之自动收集统计信息

更新时间:2022-06-30 11:40:56

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
from dba_scheduler_windows t1,dba_scheduler_wingroup_members t2
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
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
DBMS_SCHEDULER.DISABLE(
name => '"SYS"."THURSDAY_WINDOW"',
force => TRUE); --停止任务是true
END;
/

SQL>

2.修改任务的持续时间,单位是分钟:
SQL> BEGIN
DBMS_SCHEDULER.SET_ATTRIBUTE(
name => '"SYS"."THURSDAY_WINDOW"',
attribute => 'DURATION',
value => numtodsinterval(60,'minute'));
END;
/
SQL>

3.开始执行时间,BYHOUR=2,表示2点开始执行:
SQL> BEGIN
DBMS_SCHEDULER.SET_ATTRIBUTE(
name => '"SYS"."THURSDAY_WINDOW"',
attribute => 'REPEAT_INTERVAL',
value => 'freq=daily;byday=THU;byhour=10;byminute=40;bysecond=0');
END;
/

SQL>

4.开启任务:
SQL> BEGIN
DBMS_SCHEDULER.ENABLE(
name => '"SYS"."THURSDAY_WINDOW"');
END;
/
SQL>

5.查看修改后的情况:
SQL> select t1.window_name,t1.repeat_interval,t1.duration
from dba_scheduler_windows t1,dba_scheduler_wingroup_members t2
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;