Oracle Database Tuning ADDM

ADDM (Automatic Database Diagnostic Monitor) implements the Oracle performance method and analyzes statistics to provide automatic diagnosis of major performance problems. Because ADDM can significantly shorten the time required to improve the performance of a system, it is one of the most used performance tuning tools of Oracle database.
1. Run some operations on your database instance.
First, start your database instance and do the database operations (select, update, delete...) which will be optimized. e.g. run a script to make some queries in database:
sh run.sh -r rdf1mm-performance -t p -f p3.txt
2. Login to EM
Login to Database EM home page (https://:5500/em), click Performance tab.

3. Run ADDM
Click Button "Run ADDM Now", and click "Yes" on the confirmation page. After a while, we will see the ADDM analysis page.

Database Activity chart shows the database activity during the ADDM analysis period.
In the ADDM Performance Analysis table, ADDM findings are listed in descending order, from highest to least impact. The Informational Findings section lists areas that have no performance impact and are for information only.
4. Implement ADDM recommendations
Click the ADDM findings that has the impact on performance. e.g. Top SQL Statements.

The Category column displays the category of recommendation. The Benefit column displays the estimated benefit of implementing the recommendation.
If we click "Run Advisor Now", SQL tuning advisor will give us some recommendations on how to tune the SQLs.