Use SQLTuningAdvisor to optimize SQL statements for Oracle11g

In the CBO mode, the optimizer determines whether to use full table scan or index. The optimizer compares all possible methods and selects the lowest cost method.

Using SQL Tuning Advisor and SQL Access Advisor, you can call the optimizer in advisory mode to check an SQL statement or a group of SQL statements to improve their efficiency. SQL Tuning Advisor and SQL Access Advisor can provide a series of suggestions. SQL Access Advisor is mainly responsible for providing mode modification suggestions, such as adding or dropping indexes and materialized views. SQL Tuning Advisor provides other suggestions, such as creating an SQL Profile and restructuring an SQL statement. If you can achieve significant performance improvement by creating an index, SQL Tuning Avisor is also recommended. However, these suggestions are verified in SQL Access Advisor, this SQL Advisor uses SQL workload that contains a set of typical SQL statements.

ADDM automatically recognizes high-load SQL statements, and can also use SQL Tuning Advisor manually. There are two ways to use it manually, one is to call a package, such as dave dai's article: http://blog.csdn.net/tianlesoftware/article/details/5630888, one is to use DBconsole (the entry is Related links-> Advisor Central-> SQL Advisors), step by step method is as follows: http://docs.oracle.com/cd/B28359_01/server.111/b28275/tdppt_sqltune.htm#TDPPT160.