Oracle 11g 數據庫有三個預定義自動維護任務：
Automatic Optimizer Statistics Collection（自動優化器統計信息收集）
收集數據庫中所有無統計信息或僅有過時統計信息的 Schema 對象的 Optimizer（優化器）統計信息。SQL query optimizer（SQL 查詢優化器）使用此任務收集的統計信息提高 SQL 執行的性能。
Automatic Segment Advisor（自動段指導）
識別有可用回收空間的段，並提出如何消除這些段中的碎片的建議。您也可以手動運行 Segment Advisor 獲取更多最新建議，或獲取 Automatic Segment Advisor 沒有檢查到的那些有可能做空間回收的段的建議。
Automatic SQL Tuning Advisor（自動 SQL 優化指導）
檢查高負載 SQL 語句的性能，並提出如何優化這些語句的建議。您可以配置此指導，自動應用建議的SQL profile。
Standard 11g jobs are:
1. ORA$AUTOTASK_CLEAN
- the 10g jobs
- ORA$AUTOTASK_CLEAN
- HM_CREATE_OFFLINE_DICTIONARY
- DRA_REEVALUATE_OPEN_FAILURES
- MGMT_CONFIG_JOB
- MGMT_STATS_CONFIG_JOB
- BSLN_MAINTAIN_STATS_JOB
- XMLDB_NFS_CLEANUP_JOB
- RSE$CLEAN_RECOVERABLE_SCRIPT
- SM$CLEAN_AUTO_SPLIT_MERGE
The job is created by the 11g script catmwin.sql - Catalog script for Maintenance WINdow
catmwin.sql defines maintenance window and stats collection job. This job is an autotask repository data ageing job and deletes obsolete AUTOTASK repository data. The delete of this old data will be performed by the procedure ora$age_autotask_data which will be executed by the job.
2. HM_CREATE_OFFLINE_DICTIONARY
The job is created by the 11g script catmwin.sql which mentions that this is a job for creation of offline dictionary for Database Repair Advisor.
From unpublished Note 602459.1 - 'What Is OFFLINE_DICTIONARY': 'The system job SYS.HM_CREATE_OFFLINE_DICTIONARY executes the dbms_hm.create_offline_dictionary package which creates a LogMiner offline dictionary in the ADR for DRA name translation service. The job for generating the logminer dictionary is scheduled during the maintenance window. This job can be disabled. '
3. DRA_REEVALUATE_OPEN_FAILURES
The job is created by the 11g script catmwin.sql which mentions that this is a job for reevaluate open failures for Database Recovery Advisor. In other words it is used to get assistance in case of loss or corruption of datafiles, redo log files or controlfiles.
The job executes the procedure dbms_ir.reevaluateopenfailures.
Note.466682.1 - 'Data Recovery Advisor -Reference Guide'.
4. MGMT_CONFIG_JOB - comes with the OCM(Oracle Configuration Manager) installation - This is a configuration collection job.
The job is created by the script ocmjb10.sql by running procedure 'ORACLE_OCM.MGMT_CONFIG.collect_config'.
5. MGMT_STATS_CONFIG_JOB
This is an OCM Statistics collection job created in ocmjb10.sql by running 'ORACLE_OCM.MGMT_CONFIG.collect_stats'.
6. BSLN_MAINTAIN_STATS_JOB
This job is a compute statistics job. This job runs the BSLN_MAINTAIN_STATS_PROG program on the BSLN_MAINTAIN_STATS_SCHED schedule. The program BSLN_MAINTAIN_STATS_PROG will keep the default baseline's statistics up-to-date.
7. XMLDB_NFS_CLEANUP_JOB
The job is created in xdbu102.sql and runs the procedure dbms_xdbutil_int.cleanup_expired_nfsclients.
8. RSE$CLEAN_RECOVERABLE_SCRIPT - this job is STREAMS related.
It is created in execstr.sql and is new in 11.2. The script execstr.sql executes anonymous blocks for STReam. The job is responsible with the cleaning of recoverable scripts and calls 'sys.dbms_streams_auto_int.clean_recoverable_script;'.
9. SM$CLEAN_AUTO_SPLIT_MERGE - this job is STREAMS related. It is created in file execstr.sql and is new in 11.2 too. The job is responsible with the cleaning of auto split merge views.
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它們在 Oracle10g 中爲獨立作業，且在 DBA_SCHEDULER_JOBS.JOB_NAME 中可見。
這在 Oracle11g 中有所更改。相關視圖爲 DBA_AUTOTASK_WINDOW_CLIENTS。
現在，這些作業只有當被真正執行時，纔在 DBA_SCHEDULER_JOBS 中可見，且名稱爲系統生成的名稱。
SQL> desc DBA_AUTOTASK_WINDOW_CLIENTS
Name Null? Type
----------------------------------------- -------- ----------------------------
WINDOW_NAME NOT NULL VARCHAR2(30)
WINDOW_NEXT_TIME TIMESTAMP(6) WITH TIME ZONE
WINDOW_ACTIVE VARCHAR2(5)
AUTOTASK_STATUS VARCHAR2(8)
OPTIMIZER_STATS VARCHAR2(8)
SEGMENT_ADVISOR VARCHAR2(8)
SQL_TUNE_ADVISOR VARCHAR2(8)
HEALTH_MONITOR VARCHAR2(8)
select * from DBA_AUTOTASK_WINDOW_CLIENTS;
WINDOW_NAME
------------------------------
WINDOW_NEXT_TIME
---------------------------------------------------------------------------
WINDO AUTOTASK OPTIMIZE SEGMENT_ SQL_TUNE HEALTH_M
----- -------- -------- -------- -------- --------
MONDAY_WINDOW
08-DEC-08 10.00.00.000000 PM EUROPE/VIENNA
FALSE ENABLED ENABLED ENABLED ENABLED DISABLED
...
SUNDAY_WINDOW
07-DEC-08 06.00.00.000000 AM EUROPE/VIENNA
FALSE ENABLED ENABLED ENABLED ENABLED DISABLED
7 rows selected.
要啓用或禁用所有窗口的所有自動維護任務，在不使用任何參數的情況下調用 ENABLE 或 DISABLE 程序。SQL> execute DBMS_AUTO_TASK_ADMIN.DISABLE;
要禁用特定維護任務，使用 DISABLE 程序，如下所示：SQL> BEGIN
dbms_auto_task_admin.disable(
client_name => 'sql tuning advisor',
operation => NULL,
window_name => NULL);
END;
/
要再次啓用該特定維護任務，使用 ENABLE 程序，如下所示：SQL> BEGIN
dbms_auto_task_admin.enable(
client_name => 'sql tuning advisor',
operation => NULL,
window_name => NULL);
END;
/
client_name 參數使用的任務名稱列在 DBA_AUTOTASK_CLIENT 數據庫字典視圖中。示例：auto optimizer stats collection
auto space advisor
sql tuning advisor
另一個差異是預定義調度程序窗口：
- Oracle10g : WEEKNIGHT_WINDOW and WEEKEND_WINDOW
- Oracle11g : MONDAY_WINDOW .... SUNDAY_WINDOW.
爲了向下兼容，WEEKNIGHT_WINDOW 和 WEEKEND_WINDOW 仍然存在。
窗口打開持續的時間在 11g 中有所更改。星期一到星期五從晚上 10 點到凌晨 2 點，星期六到星期日從上午 6 點到凌晨 2 點。
您可以使用 DBMS_SCHEDULER.SET_ATTRIBUTE 程序調整預定義維護窗口時間，使其適用於您的數據庫環境。示例：以下腳本將 WEEKNIGHT_WINDOW 改爲每個工作日從午夜至上午 8 點（窗口持續時間爲 8 小時不變）：EXECUTE DBMS_SCHEDULER.SET_ATTRIBUTE(
'WEEKNIGHT_WINDOW',
'repeat_interval',
'freq=daily;byday=MON, TUE, WED, THU, FRI;byhour=0;byminute=0;bysecond=0');
每個窗口還有一個名爲 DEFAULT_MAINTENANCE_PLAN 的預定義資源計劃，一旦打開相關窗口，該計劃將激活。這是 10g 和 11g 之間的另一個差異。
SQL> select window_name, resource_plan from dba_scheduler_windows;
WINDOW_NAME RESOURCE_PLAN
------------------------------ ------------------------------
MONDAY_WINDOW DEFAULT_MAINTENANCE_PLAN
TUESDAY_WINDOW DEFAULT_MAINTENANCE_PLAN
WEDNESDAY_WINDOW DEFAULT_MAINTENANCE_PLAN
THURSDAY_WINDOW DEFAULT_MAINTENANCE_PLAN
FRIDAY_WINDOW DEFAULT_MAINTENANCE_PLAN
SATURDAY_WINDOW DEFAULT_MAINTENANCE_PLAN
SUNDAY_WINDOW DEFAULT_MAINTENANCE_PLAN
WEEKNIGHT_WINDOW
WEEKEND_WINDOW
9 rows selected.SQL> select * from dba_rsrc_plans where plan='DEFAULT_MAINTENANCE_PLAN'
PLAN_ID PLAN NUM_PLAN_DIRECTIVES
---------- ------------------------------ -------------------
CPU_METHOD MGMT_METHOD
------------------------------ ------------------------------
ACTIVE_SESS_POOL_MTH PARALLEL_DEGREE_LIMIT_MTH
------------------------------ ------------------------------
QUEUEING_MTH SUB
------------------------------ ---
COMMENTS
--------------------------------------------------------------------------------
STATUS MAN
------------------------------ ---
11187 DEFAULT_MAINTENANCE_PLAN 4
EMPHASIS EMPHASIS
ACTIVE_SESS_POOL_ABSOLUTE PARALLEL_DEGREE_LIMIT_ABSOLUTE
FIFO_TIMEOUT NO
Default plan for maintenance windows that prioritizes SYS_GROUP operations and a
llocates the remaining 5% to diagnostic operations and 25% to automated maintena
nce operations.
YESSQL> select * from DBA_RSRC_PLAN_DIRECTIVES where plan='DEFAULT_MAINTENANCE_PLAN';
PLAN GROUP_OR_SUBPLAN TYPE
------------------------------ ------------------------------ --------------
CPU_P1 CPU_P2 CPU_P3 CPU_P4 CPU_P5 CPU_P6 CPU_P7
---------- ---------- ---------- ---------- ---------- ---------- ----------
CPU_P8 MGMT_P1 MGMT_P2 MGMT_P3 MGMT_P4 MGMT_P5 MGMT_P6
---------- ---------- ---------- ---------- ---------- ---------- ----------
MGMT_P7 MGMT_P8 ACTIVE_SESS_POOL_P1 QUEUEING_P1 PARALLEL_DEGREE_LIMIT_P1
---------- ---------- ------------------- ----------- ------------------------
SWITCH_GROUP SWITC SWITCH_TIME SWITCH_IO_MEGABYTES
------------------------------ ----- ----------- -------------------
SWITCH_IO_REQS SWITC MAX_EST_EXEC_TIME UNDO_POOL MAX_IDLE_TIME
-------------- ----- ----------------- ---------- -------------
MAX_IDLE_BLOCKER_TIME SWITCH_TIME_IN_CALL
--------------------- -------------------
COMMENTS
--------------------------------------------------------------------------------
STATUS MAN
------------------------------ ---
DEFAULT_MAINTENANCE_PLAN SYS_GROUP CONSUMER_GROUP
100 0 0 0 0 0 0
0 100 0 0 0 0 0
0 0
FALSE
FALSE
Directive for system operations
NO
DEFAULT_MAINTENANCE_PLAN OTHER_GROUPS CONSUMER_GROUP
0 70 0 0 0 0 0
0 0 70 0 0 0 0
0 0
FALSE
FALSE
Directive for all other operations
NO
DEFAULT_MAINTENANCE_PLAN ORA$AUTOTASK_SUB_PLAN PLAN
0 25 0 0 0 0 0
0 0 25 0 0 0 0
0 0
FALSE
FALSE
Directive for automated maintenance tasks
NO
DEFAULT_MAINTENANCE_PLAN ORA$DIAGNOSTICS CONSUMER_GROUP
0 5 0 0 0 0 0
0 0 5 0 0 0 0
0 0
FALSE
FALSE
Directive for automated diagnostic tasks
NO
10g 與 11g 之間變化的摘要：
主題 10g 11g 作業 在 DBA_SCHEDULER_JOBS 中獨立作業 AUTOTASKS 有命名前綴“ORA$AT”，且只有作業執行後纔可見 維護窗口 2 個窗口：WEEKNIGHT 和 WEEKEND 每天有不同的窗口 Resource manager 默認不啓用 每個窗口都有預定義資源計劃