12C-OCP升级1z-060-021

Which three functions are performed by the SQL Tuning Advisor?

 

A. Building and implementing SQL profiles 

B. Recommending the optimization of materialized views 

C. Checking query objects for missing and stale statistics 

D. Recommending bitmap, function-based, and B-tree indexes 

E. Recommending the restructuring of SQL queries that are using bad plans 

 
Answer: A,C,E

答案解析：

在12C 官方文档的位置：
http://docs.oracle.com/database/121/TGSQL/tgsql_sqltune.htm#TGSQL540

Purpose of SQL Tuning Advisor

SQL Tuning Advisor is a mechanism for resolving problems related to suboptimally performing SQL statements. Use SQL Tuning Advisor to obtain recommendations for improving performance of high-load SQL statements, and prevent regressions by only executing optimal
plans.

Tuning recommendations include:

Collection of object statistics

Creation of indexes

Rewriting SQL statements

Creation of SQL profiles

Creation of SQL plan baselines

The SQL Tuning Advisor takes one or more SQL statements as an input and

invokes the Automatic Tuning Optimizer to perform SQL tuning on the statements. The

output of the SQL Tuning Advisor is in the form of an advice or recommendations, along

with a rationale for each recommendation and its expected benefit. The recommendation

relates to collection of statistics on objects (C), creation of new indexes, restructuring of the

SQL statement (E), or creation of a SQL profile (A). You can choose to accept the

recommendation to complete the tuning of the SQL statements. 

B，D这两个答案是SQL ACCESS ADVISOR这个工作所完成的