Oracle 性能报告 ADDM

自动数据库性能诊断: ADDM(Automatic Database Diagnostic Monitor)

这种技术是基于AWR技术的，原理就是比较两个AWR快照。

1、获取到两次AWR快照的ID:

SELECT SNAP_ID, TO_CHAR(BEGIN_INTERVAL_TIME,'yyyy-mm-dd hh24:mi:ss') BEGIN_INTERVAL_TIME, TO_CHAR(STARTUP_TIME,'yyyy-mm-dd hh24:mi:ss') STARTUP_TIME FROM DBA_HIST_SNAPSHOT ORDER BY 1;
会得到类似如下的列表：

SNAP_ID BEGIN_INTERVAL_TIME STARTUP_TIME
---------- ------------------- -------------------
5 2012-11-29 22:27:35 2012-11-29 22:16:28
6 2012-11-30 20:22:57 2012-11-29 22:16:28
7 2012-11-30 21:00:59 2012-11-29 22:16:28
8 2012-12-01 17:22:40 2012-11-29 22:16:28
9 2012-12-01 18:39:16 2012-12-01 18:39:16
10 2012-12-01 19:00:22 2012-12-01 18:39:16
11 2012-12-01 20:00:25 2012-12-01 18:39:16
12 2012-12-08 19:21:19 2012-12-08 19:21:19
13 2012-12-08 19:32:34 2012-12-08 19:21:19
14 2012-12-08 21:00:40 2012-12-08 19:21:19
15 2012-12-09 16:10:05 2012-12-08 19:21:19

2、运行报告生成工具
@?/rdbms/admin/addmrpt
输入 begin_snap 的值: 7

输入 end_snap 的值: 14
输入 report_name 的值:
Report written to addmrpt_1_1199_1200.txt
查看addmrpt_1_1199_1200.txt文件内容即可。

配合其使用的还有一个
SQL Tuning Advisor:

1、创建优化任务并执行:
DECLARE
my_task_name VARCHAR2(30);
my_sqltext CLOB;
BEGIN
my_sqltext := 'select a.table_name, b.object_id from bigtab b, smalltab a';
my_task_name := DBMS_SQLTUNE.CREATE_TUNING_TASK(
sql_text => my_sqltext,
user_name => 'SCOTT',
scope => 'COMPREHENSIVE',
time_limit => 60,
task_name => 'sql_tuning_task_1',
description => '');
dbms_sqltune.Execute_tuning_task (task_name => 'sql_tuning_task_1');
END;
/

2、查看优化建议结果
set long 10000
set linesize 100
SELECT DBMS_SQLTUNE.REPORT_TUNING_TASK('sql_tuning_task_1') FROM DUAL;

删除优化任务:

EXEC DBMS_SQLTUNE.DROP_TUNNING_TASK('sql_tuning_task_1');