Oracle11g系統自動收集統計信息的一些知識
---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
--禁用自動收集
exec DBMS_AUTO_TASK_ADMIN.DISABLE(client_name => 'auto optimizer stats collection',operation => NULL,window_name => NULL);
--啟用自動收集
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
--收集當前數據庫下所有用戶的統計信息
exec dbms_stats.gather_database_stats(user);
--收集當前數據庫用戶下所有對象的統計信息
exec dbms_stats.gather_schema_stats(user);
--收集數據字典的統計信息
exec dbms_stats.gather_dictionary_stats();
--獲取global的統計信息收集設置選項
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;
--設置global的統計信息收集選項
EXEC DBMS_STATS.SET_PARAM('DEGREE',4);
