Oracle ADDM报告生成和性能分析

我写的SQL调优专栏：https://blog.csdn.net/u014427391/article/category/8679315

对于局部的，比如某个页面列表sql，我们可以使用Oracle的执行计划进行sql调优，但是对于整个系统来说，你可以知道哪些sql比较耗时？当然可以通过查Oracle的共享池得到，不过Oracle系统本身就提供了几种性能分析报告，比如AWR、ASH、ADDM、AWRDD等等报告，本博客介绍一下ADDM性能分析报告

ADDM全称是Automatic Database Diagnostic Monitor，是Oracle一个实现性能自我诊断的最佳利器。它依赖于AWR，也就是说ADDM要诊断，必要要有诊断的依据。在Oracle中，这个诊断依据就是Oracle AWR，因为Oracle AWR会定期的收集整个数据库在运行期间的性能统计数据。

一、ADDM报告生成

继之前AWR、ASH方面的博客之后，https://smilenicky.blog.csdn.net/article/details/89414432，https://smilenicky.blog.csdn.net/article/details/89419185，我再写一篇ADDM方面的博客：

1.1 工具选择

对于Oracle数据库可以使用sqlplus或者plsql developer客户端软件

sqlplus 使用

可以使用sqlplus工具登录

进入数据库

sqlplus / as sysdba

查看用户

show parameter db_name

用登录之后才可以使用

plsql developer使用

plsql developer也可以使用，登录之后，选择文件(File)->新建(New)->命令窗口(Command Window)

1.2 自动创建快照

开始压测后执行

exec DBMS_WORKLOAD_REPOSITORY.CREATE_SNAPSHOT ();

可以通过dba_hist_wr_control查看当前的配置情况，当前awr为每1小时做一次数据快照，保留时间为8天。

 select * from dba_hist_wr_control;

修改配置，每隔30分钟收集一次，保存1天

execute dbms_workload_repository.modify_snapshot_settings(interval=>30,retention=>14000);

关闭自动收集

SQL>exec dbms_workload_repository.modify_snapshot_settings (interval=>0,retention=>24*60);

1.3 手工创建快照

除了自动创建快照，也可以手工创建快照

select dbms_workload_repository.create_snapshot() from dual;

1.4 ADDM报告生成

对于sqlplus客户端的可以使用

@?/rdbms/admin/addmrpt.sql

对于plsql客户端，我用绝对路径去执行，@?的命令找不到文件

这个要根据自己的Oracle安装路径去修改，例如：

    @D:/oracle/product/11.1.0/db_1/RDBMS/ADMIN/addmrpt.sql

（1）快照开始id

Enter value for begin_snap:418

要根据日志打印的快照id范围来填，所以我可以填写：418

（2）快照结束id

Enter value for end_snap:420

要根据日志打印的快照id范围来填，所以我可以填写：420

（3）ADDM报告名称

Enter value for report_name

填写ADDM报告的名称，我可以填写addm_20190421.html，然后在打印的日志里有文件保存的路径：，比如：D:\oracle\product\11.2.0\dbhome_1\RDBMS\ADMIN\addm.html

SQL> @D:/oracle/product/11.2.0/dbhome_1/RDBMS/ADMIN/addmrpt.sql
Current Instance
~~~~~~~~~~~~~~~~
      DBID DB_NAME      INST_ INST_NAME
---------- ------------ ----- ------------
1525762377 ORCL             1 orcl
Cannot SET TRIMSPOOL
Cannot SET UNDERLINE
Instances in this Workload Repository schema
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DBBID        INSTT DBB_NAME     INSTT_NAME   HOST
------------ ----- ------------ ------------ ------------
* 1525762377     1 ORCL         orcl         PC-201508171
                                             906
Using 1525762377 for database Id
Using 1 for instance number
PL/SQL procedure successfully completed
dbid
---------
1525762377
inst_num
---------
1
PL/SQL procedure successfully completed
inst_num
---------
1
dbid
---------
1525762377
max_snap_time
---------
18/04/2019
Specify the number of days of snapshots to choose from
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Entering the number of days (n) will result in the most recent
(n) days of snapshots being listed.  Pressing <return> without
specifying a number lists all completed snapshots.
Listing the last 3 days of Completed Snapshots
INST_NAME    DB_NAME       SNAP_ID SNAPDAT            LV
------------ ------------ -------- ------------------ --
orcl         ORCL              417 16 Apr 2019 00:00   1
orcl         ORCL              418 16 Apr 2019 19:48   1
orcl         ORCL              419 16 Apr 2019 21:00   1
orcl         ORCL              420 16 Apr 2019 22:00   1
orcl         ORCL              421 16 Apr 2019 23:00   1
orcl         ORCL              422 17 Apr 2019 21:20   1
orcl         ORCL              423 17 Apr 2019 22:00   1
orcl         ORCL              424 17 Apr 2019 23:00   1
orcl         ORCL              425 18 Apr 2019 00:00   1
orcl         ORCL              426 18 Apr 2019 21:26   1
orcl         ORCL              427 18 Apr 2019 22:00   1
11 rows selected
dbid
---------
1525762377
inst_num
---------
1
max_snap_time
---------
18/04/2019
Specify the Begin and End Snapshot Ids
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Begin Snapshot Id specified: 418
End   Snapshot Id specified: 420
PL/SQL procedure successfully completed
bid
---------
418
eid
---------
420
PL/SQL procedure successfully completed
inst_num
---------
1
dbid
---------
1525762377
bid
---------
418
eid
---------
420
Cannot SET TRIMSPOOL
Cannot SET UNDERLINE
Specify the Report Name
~~~~~~~~~~~~~~~~~~~~~~~
The default report file name is addmrpt_1_418_420.txt.  To use this name,
press <return> to continue, otherwise enter an alternative.
Using the report name addm.html
Running the ADDM analysis on the specified pair of snapshots ...
bid
---------
418
eid
---------
420
inst_num
---------
1
dbid
---------
1525762377
task_name
---------
TASK_953
Generating the ADDM report for this analysis ...
Started spooling to D:\oracle\product\11.2.0\dbhome_1\RDBMS\ADMIN\addm.html
          ADDM Report for Task 'TASK_953'
          -------------------------------
Analysis Period
---------------
AWR snapshot range from 418 to 420.
Time period starts at 16-APR-19 07.48.09 PM
Time period ends at 16-APR-19 10.00.20 PM
Analysis Target
---------------
Database 'ORCL' with DB ID 1525762377.
Database version 11.2.0.1.0.
ADDM performed an analysis of instance orcl, numbered 1 and hosted at
PC-201508171906.
Activity During the Analysis Period
-----------------------------------
Total database time was 57 seconds.
The average number of active sessions was .01.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
There are no findings to report.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
          Additional Information
          ----------------------
Miscellaneous Information
-------------------------
There was no significant database activity to run the ADDM.
The database's maintenance windows were active during 99% of the analysis
period.
task_name
---------
TASK_953
Stopped spooling to D:\oracle\product\11.2.0\dbhome_1\RDBMS\ADMIN\addm.html
End of Report
Report written to addm.html.

二、ADDM报告性能分析

ADDM性能报告是从数据库的整体配置和局部SQL方面给出建议，阅读时候按FINDING1，FINDING2，...，的顺序阅读就好

下面的图来自《收获，不止SQL优化》一书：