Oracle 11g系统自动收集统计信息的一些知识

---11g的是 周一到周五 22：00-2：00 周六周日 6：00-4：00
SELECT w.window_name, w.repeat_interval, w.duration, w.enabled
FROM dba_autotask_window_clients c, dba_scheduler_windows w
WHERE c.window_name = w.window_name
AND c.optimizer_stats = 'ENABLED';
WINDOW_NAME          REPEAT_INTERVAL                                              DURATION
-------------------- ------------------------------------------------------------ ---------------
SUNDAY_WINDOW        freq=daily;byday=SUN;byhour=6;byminute=0; bysecond=0         +000 20:00:00
FRIDAY_WINDOW        freq=daily;byday=FRI;byhour=22;byminute=0; bysecond=0        +000 04:00:00
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
MONDAY_WINDOW        freq=daily;byday=MON;byhour=22;byminute=0; bysecond=0        +000 04:00:00

--禁用自动收集
exec DBMS_AUTO_TASK_ADMIN.DISABLE(client_name => 'auto optimizer stats collection',operation => NULL,window_name => NULL);
--启用自动收集
exec DBMS_AUTO_TASK_ADMIN.ENABLE(client_name => 'auto optimizer stats collection',operation => NULL,window_name => NULL);
--查看job

select client_name,status from dba_autotask_client;

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

--收集当前数据库下所有用户的统计信息
exec dbms_stats.gather_database_stats(user);
--收集当前数据库用户下所有对象的统计信息
exec dbms_stats.gather_schema_stats(user);
--收集数据字典的统计信息
exec dbms_stats.gather_dictionary_stats();
--获取global的统计信息收集设置选项
select dbms_stats.get_prefs('method_opt') from dual;
select dbms_stats.get_prefs('concurrent') from dual; 
select dbms_stats.get_prefs('GRANULARITY') from dual;
--设置global的统计信息收集选项
EXEC DBMS_STATS.SET_PARAM('DEGREE',4);