自动维护任务是一种按规则自动启动的数据库维护操作任务。比如自动收集为查询优化器使用的统计信息。自动维护任务按维护窗口自动

最近看到alter日志里面有VKRM的报错信息，，所以查询学习了下。

From Oracle 11g, each day has its own windows and each of it has been specified default resource plan.This is something new for me too.So, i think that would be reason for seeing VKRM process in the alert log.



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



SYS@>AppD> SELECT WINDOW_GROUP_NAME,ENABLED,NEXT_START_DATE,COMMENTS FROM DBA_SCHEDULER_WINDOW_GROUPS



WINDOW_GROUP_NAME ENABL NEXT_START_DATE COMMENTS

-------------------------- ---------------------------------------- --------------------------------------

MAINTENANCE_WINDOW_GROUP TRUE 14-MAR-11 10.00.00.000000 PM Window group for Automated Maintenance

ORA$AT_WGRP_OS TRUE 14-MAR-11 10.00.00.000000 PM auto optimizer stats collection

ORA$AT_WGRP_SA TRUE 14-MAR-11 10.00.00.000000 PM auto space advisor

ORA$AT_WGRP_SQ TRUE 14-MAR-11 10.00.00.000000 PM sql tuning advisor



SQL> select client_name ,status from DBA_AUTOTASK_CLIENT;



CLIENT_NAME STATUS

---------------------------------------------------------------- --------

auto optimizer stats collection ENABLED

auto space advisor ENABLED

sql tuning advisor ENABLED



自动维护任务是一种按规则自动启动的数据库维护操作任务。比如自动收集为查询优化器使用的统计信息。自动维护任务按维护窗口自动运行。所谓自动维护窗口是按照预定义的间隔时间窗口。