使用ADDM

有两种方式使用ADDM

OEM
WhilethesimplestwaytorunanADDManalysisoveraspecifictimeperiodiswith
the Oracle Enterprise Manager GUI,

SCRIPT

 ADDM can also be run manually using the
$ORACLE_HOME/rdbms/admin/addmrpt.sql script

@$ORACLE_HOME/rdbms/admin/addmrpt.sql

API
and DBMS_ADVISOR package APIs.

手动运行需要必备的权限：ADVISOR privilege
The SQL script and APIs can be run by any user who has been
granted the ADVISOR privilege

DBA_ADVISOR views.

DBA_ADVISOR_TASKS
This view provides basic information about existing tasks, such as the task Id,
task name, and when created.

DBA_ADVISOR_LOG
This view contains the current task information, such as status, progress, error
messages, and execution times.

DBA_ADVISOR_RECOMMENDATIONS
This view displays the results of completed diagnostic tasks with
recommendations for the problems identified in each run. The
recommendations should be looked at in the order of the RANK column, as this
relays the magnitude of the problem for the recommendation. The BENEFIT
column gives the benefit to the system you can expect after the
recommendation is carried out.

DBA_ADVISOR_FINDINGS
This view displays all the findings and symptoms that the diagnostic monitor
encountered along with the specific recommendation

ADDM配置

默认是安装并且启用。确认是否启用，查看初始化参数：STATISTICS_LEVEL
STATISTICS_LEVEL
Automatic database diagnostic monitoring is enabled by default and is controlled
by the STATISTICS_LEVEL initialization parameter. The STATISTICS_LEVEL
parameter should be set to the TYPICAL or ALL to enable the automatic database
diagnostic monitoring. The default setting is TYPICAL. Setting STATISTICS_
LEVEL to BASIC disables many Oracle features, including ADDM, and is strongly
discouraged

DBIO_EXPECTED

ADDM analysis of I/O performance partially depends on a single argument, DBIO_
EXPECTED, that describes the expected performance of the I/O subsystem. The
value of DBIO_EXPECTED is the average time it takes to read a single database
block in microseconds. Oracle uses the default value of 10 milliseconds, which is an
appropriate value for most modern hard drives. If your hardware is significantly
different, such as very old hardware or very fast RAM disks, consider using a
different value.