11g: Scheduler Maintenance Tasks or Autotasks [ID 756734.1] - 重庆思庄Oracle、Redhat认证学习论坛

This bulletin gives more information about the Automated Maintenance Tasks or AUTOTASK jobs which are a new setup in 11g for certain System generated maintenance jobs.

It indentifies some key differences between 10g and 11g related to the Maintenance Tasks.

Scope and Application

11g: Scheduler Maintenance Tasks or Autotasks

Introduction

Implementation

In Oracle10g they were created as separate jobs and visible in DBA_SCHEDULER_JOBS.JOB_NAME.

This has changed in Oracle 11g. The related view is DBA_AUTOTASK_WINDOW_CLIENTS.
The jobs are now only visible in DBA_SCHEDULER_JOBS with their system generated name once they are really executed.

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.

The WEEKNIGHT_WINDOW and WEEKEND_WINDOW are still there for backwards compatibility.

EXECUTE DBMS_SCHEDULER.SET_ATTRIBUTE(
   'WEEKNIGHT_WINDOW', 
   'repeat_interval',
   'freq=daily;byday=MON, TUE, WED, THU, FRI;byhour=0;byminute=0;bysecond=0');

Each weekday window also has a pre-defined Resource Plan called DEFAULT_MAINTENANCE_PLAN, which will become active once the related window opens. This is another difference between 10g and 11g.

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.
YES

SQL> 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

Summary of changes between 10g and 11g :

Subject	10g	11g
Jobs	Separate jobs in DBA_SCHEDULER_JOBS	AUTOTASKS has a naming prefix 'ORA$AT' and are only visible as a job once executed
Maintenance Window	2 windows, WEEKNIGHT and WEEKEND	Each day has its own window
Resource manager	Not enabled per default	Pre-defined Resource Plan for every weekday window

Related views :

DBA_AUTOTASK_CLIENT
DBA_AUTOTASK_CLIENT_HISTORY
DBA_AUTOTASK_CLIENT_JOB
DBA_AUTOTASK_JOB_HISTORY
DBA_AUTOTASK_OPERATION
DBA_AUTOTASK_SCHEDULE
DBA_AUTOTASK_TASK
DBA_AUTOTASK_WINDOW_CLIENTS
DBA_AUTOTASK_WINDOW_HISTORY

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Applies to:

Purpose

Scope and Application