oracle ADDM

addm干的活：
1分析awr数据
2诊断性能问题根源
3提供修正问题建议
4标识系统非问题区
addm提供下面的好处：
1默认每小时自动生成性能诊断报告
2吹嘘诊断有经验，活好
3能标识问题根源
4对系统影响小
分析的目的是降低db time,db time包含等待时间和非空闲会话的cpu时间。
感觉这个工具在做完压测后，可以参考下，看看有哪些问题。
安装：
addm默认情况下是启用的，受control_management_pack_access和statistics_level初始化参数控制。
在数据库模式下运行，这个会分析数据库所有的实例，需要执行如下的存储过程：
BEGIN
DBMS_ADDM.ANALYZE_DB (
task_name IN OUT VARCHAR2,
begin_snapshot IN NUMBER,
end_snapshot IN NUMBER,
db_id IN NUMBER := NULL);
END;
/
在实例级别运行：
BEGIN
DBMS_ADDM.ANALYZE_INST (
task_name IN OUT VARCHAR2,
begin_snapshot IN NUMBER,
end_snapshot IN NUMBER,
instance_number IN NUMBER := NULL,
db_id IN NUMBER := NULL);
END;
/
获取text的报告
DBMS_ADDM.GET_REPORT (
task_name IN VARCHAR2
RETURN CLOB);
SET LONG 1000000 PAGESIZE 0;
SELECT DBMS_ADDM.GET_REPORT(:tname) FROM DUAL;

也可以用视图查看结果
DBA_ADVISOR_FINDINGS

This view displays all the findings discovered by all advisors. Each finding is displayed with an associated finding ID, name, and type. For tasks with multiple executions, the name of each task execution associated with each finding is also listed.

DBA_ADDM_FINDINGS

This view contains a subset of the findings displayed in the related DBA_ADVISOR_FINDINGS view. This view only displays the ADDM findings discovered by all advisors. Each ADDM finding is displayed with an associated finding ID, name, and type.

DBA_ADVISOR_FINDING_NAMES

List of all finding names registered with the advisor framework.

DBA_ADVISOR_RECOMMENDATIONS

This view displays the results of completed diagnostic tasks with recommendations for the problems identified in each execution. The recommendations should be reviewed in the order of the RANK column, as this relays the magnitude of the problem for the recommendation. The BENEFIT column displays the benefit to the system you can expect after the recommendation is performed. For tasks with multiple executions, the name of each task execution associated with each advisor task is also listed.

DBA_ADVISOR_TASKS

This view provides basic information about existing tasks, such as the task ID, task name, and when the task was created. For tasks with multiple executions, the name and type of the last or current execution associated with each advisor task is also listed.