从Oracle 11g开始，Oracle的自动化维护任务更智能化了，默认情况下，在安装数据库的过程中，如果启用自动化维护任务的话，数据库会在工作日的每晚22:00到第二天的凌晨2:00，周末的凌晨6:00到第二天的凌晨2:00,自动对数据库进行诸如优化器的统计信息收集、自动SQL的优化。且在自动化维护的过程中，数据库会使用较少的CPU资源，以防止自动化维护任务使用到过多的资源而影响到用户的正常使用。

           其一，在使用DBCA建库的时候，我们可以看到这一自动维护任务的选项：

           其二，如果启用了自动化维护任务的话，也可以从数据库的alert日志里看到下述信息：

Fri Mar 23 22:00:00 2012
Setting Resource Manager plan SCHEDULER[0x3007]:DEFAULT_MAINTENANCE_PLAN via scheduler window
Setting Resource Manager plan DEFAULT_MAINTENANCE_PLAN via parameter
Fri Mar 23 22:00:00 2012
Starting background process VKRM
Fri Mar 23 22:00:00 2012
VKRM started with pid=24, OS id=10743
Fri Mar 23 22:00:33 2012
Begin automatic SQL Tuning Advisor run for special tuning task  "SYS_AUTO_SQL_TUNING_TASK"
Fri Mar 23 22:01:32 2012
End automatic SQL Tuning Advisor run for special tuning task  "SYS_AUTO_SQL_TUNING_TASK"
Fri Mar 23 22:05:56 2012
Thread 1 cannot allocate new log, sequence 8
Private strand flush not complete
  Current log# 1 seq# 7 mem# 0: +DATA/ocm11g/onlinelog/group_1.261.778667669
  Current log# 1 seq# 7 mem# 1: +FLASH/ocm11g/onlinelog/group_1.257.778667673
Thread 1 advanced to log sequence 8 (LGWR switch)
  Current log# 2 seq# 8 mem# 0: +DATA/ocm11g/onlinelog/group_2.262.778667673
  Current log# 2 seq# 8 mem# 1: +FLASH/ocm11g/onlinelog/group_2.258.778667675
Sat Mar 24 02:00:00 2012
Clearing Resource Manager plan via parameter
Sat Mar 24 06:00:00 2012
Setting Resource Manager plan SCHEDULER[0x3008]:DEFAULT_MAINTENANCE_PLAN via scheduler window
Setting Resource Manager plan DEFAULT_MAINTENANCE_PLAN via parameter
Sat Mar 24 06:00:00 2012
Starting background process VKRM
Sat Mar 24 06:00:01 2012
VKRM started with pid=29, OS id=15277
Sat Mar 24 06:00:21 2012
Begin automatic SQL Tuning Advisor run for special tuning task  "SYS_AUTO_SQL_TUNING_TASK"
Sat Mar 24 06:00:49 2012
End automatic SQL Tuning Advisor run for special tuning task  "SYS_AUTO_SQL_TUNING_TASK"
Sat Mar 24 06:02:05 2012
Thread 1 cannot allocate new log, sequence 9
Private strand flush not complete
  Current log# 2 seq# 8 mem# 0: +DATA/ocm11g/onlinelog/group_2.262.778667673
  Current log# 2 seq# 8 mem# 1: +FLASH/ocm11g/onlinelog/group_2.258.778667675
Thread 1 advanced to log sequence 9 (LGWR switch)
  Current log# 3 seq# 9 mem# 0: +DATA/ocm11g/onlinelog/group_3.263.778667677
  Current log# 3 seq# 9 mem# 1: +FLASH/ocm11g/onlinelog/group_3.259.778667677
Sat Mar 24 08:56:14 2012
Thread 1 advanced to log sequence 10 (LGWR switch)
  Current log# 1 seq# 10 mem# 0: +DATA/ocm11g/onlinelog/group_1.261.778667669
  Current log# 1 seq# 10 mem# 1: +FLASH/ocm11g/onlinelog/group_1.257.778667673
Sat Mar 24 14:06:51 2012
Thread 1 cannot allocate new log, sequence 11
Private strand flush not complete
  Current log# 1 seq# 10 mem# 0: +DATA/ocm11g/onlinelog/group_1.261.778667669
  Current log# 1 seq# 10 mem# 1: +FLASH/ocm11g/onlinelog/group_1.257.778667673
Thread 1 advanced to log sequence 11 (LGWR switch)
  Current log# 2 seq# 11 mem# 0: +DATA/ocm11g/onlinelog/group_2.262.778667673
  Current log# 2 seq# 11 mem# 1: +FLASH/ocm11g/onlinelog/group_2.258.778667675
Sat Mar 24 18:11:25 2012
Thread 1 advanced to log sequence 12 (LGWR switch)
  Current log# 3 seq# 12 mem# 0: +DATA/ocm11g/onlinelog/group_3.263.778667677
  Current log# 3 seq# 12 mem# 1: +FLASH/ocm11g/onlinelog/group_3.259.778667677
Sun Mar 25 02:00:00 2012
Clearing Resource Manager plan via parameter
Sun Mar 25 02:00:30 2012
Thread 1 advanced to log sequence 13 (LGWR switch)
  Current log# 1 seq# 13 mem# 0: +DATA/ocm11g/onlinelog/group_1.261.778667669
  Current log# 1 seq# 13 mem# 1: +FLASH/ocm11g/onlinelog/group_1.257.778667673
Sun Mar 25 06:00:00 2012
Setting Resource Manager plan SCHEDULER[0x3009]:DEFAULT_MAINTENANCE_PLAN via scheduler window
Setting Resource Manager plan DEFAULT_MAINTENANCE_PLAN via parameter
Sun Mar 25 06:00:00 2012
Starting background process VKRM
Sun Mar 25 06:00:00 2012
VKRM started with pid=29, OS id=21059
Sun Mar 25 06:00:15 2012
Begin automatic SQL Tuning Advisor run for special tuning task  "SYS_AUTO_SQL_TUNING_TASK"
Sun Mar 25 06:00:33 2012
End automatic SQL Tuning Advisor run for special tuning task  "SYS_AUTO_SQL_TUNING_TASK"
Sun Mar 25 08:56:21 2012
Thread 1 advanced to log sequence 14 (LGWR switch)
  Current log# 2 seq# 14 mem# 0: +DATA/ocm11g/onlinelog/group_2.262.778667673
  Current log# 2 seq# 14 mem# 1: +FLASH/ocm11g/onlinelog/group_2.258.778667675
Sun Mar 25 14:08:09 2012
Thread 1 cannot allocate new log, sequence 15
Private strand flush not complete
  Current log# 2 seq# 14 mem# 0: +DATA/ocm11g/onlinelog/group_2.262.778667673
  Current log# 2 seq# 14 mem# 1: +FLASH/ocm11g/onlinelog/group_2.258.778667675
Thread 1 advanced to log sequence 15 (LGWR switch)
  Current log# 3 seq# 15 mem# 0: +DATA/ocm11g/onlinelog/group_3.263.778667677
  Current log# 3 seq# 15 mem# 1: +FLASH/ocm11g/onlinelog/group_3.259.778667677
Sun Mar 25 22:08:35 2012 
Thread 1 cannot allocate new log, sequence 16
Private strand flush not complete
  Current log# 3 seq# 15 mem# 0: +DATA/ocm11g/onlinelog/group_3.263.778667677
  Current log# 3 seq# 15 mem# 1: +FLASH/ocm11g/onlinelog/group_3.259.778667677
Thread 1 advanced to log sequence 16 (LGWR switch)
  Current log# 1 seq# 16 mem# 0: +DATA/ocm11g/onlinelog/group_1.261.778667669
  Current log# 1 seq# 16 mem# 1: +FLASH/ocm11g/onlinelog/group_1.257.778667673
Mon Mar 26 02:00:00 2012 
Clearing Resource Manager plan via parameter
Mon Mar 26 10:14:25 2012 
Thread 1 advanced to log sequence 17 (LGWR switch)
  Current log# 2 seq# 17 mem# 0: +DATA/ocm11g/onlinelog/group_2.262.778667673
  Current log# 2 seq# 17 mem# 1: +FLASH/ocm11g/onlinelog/group_2.258.778667675
Mon Mar 26 22:00:00 2012 
Setting Resource Manager plan SCHEDULER[0x3003]:DEFAULT_MAINTENANCE_PLAN via scheduler window
Setting Resource Manager plan DEFAULT_MAINTENANCE_PLAN via parameter
Mon Mar 26 22:00:00 2012 
Starting background process VKRM 
Mon Mar 26 22:00:00 2012 
VKRM started with pid=24, OS id=9542 
Mon Mar 26 22:00:30 2012 
Begin automatic SQL Tuning Advisor run for special tuning task  "SYS_AUTO_SQL_TUNING_TASK"
Mon Mar 26 22:00:59 2012 
End automatic SQL Tuning Advisor run for special tuning task  "SYS_AUTO_SQL_TUNING_TASK"
Mon Mar 26 22:02:17 2012 
Thread 1 cannot allocate new log, sequence 18
Private strand flush not complete
  Current log# 2 seq# 17 mem# 0: +DATA/ocm11g/onlinelog/group_2.262.778667673
  Current log# 2 seq# 17 mem# 1: +FLASH/ocm11g/onlinelog/group_2.258.778667675
Thread 1 advanced to log sequence 18 (LGWR switch)
  Current log# 3 seq# 18 mem# 0: +DATA/ocm11g/onlinelog/group_3.263.778667677
  Current log# 3 seq# 18 mem# 1: +FLASH/ocm11g/onlinelog/group_3.259.778667677
Tue Mar 27 02:00:00 2012 
Clearing Resource Manager plan via parameter

           从上，上周五晚上22:00(Fri Mar 23 22:00:00 2012)到上周六凌晨2:00(Sat Mar 24 02:00:00 2012)数据库执行自动化维护任务，上周六、日凌晨6:00到次日凌晨2:00数据库执行自动化维护任务，本周一自动化维护任务的窗口又开始回到晚上22:00到次日凌晨2：00点之间。可见，Oracle 11g相比以前版本的数据库更加自动化、智能化。