OCP 1Z0 053 80

80.Which two statements regarding a SQL profile are true? (Choose two.) 
A. It is built by Automatic Tuning Optimizer. 
B. It cannot be stored persistently in the data dictionary. 
C. It can be used by the query optimizer automatically. 
D. It can be created manually by using the CREATE PROFILE command. 
Answer: AC 

http://docs.oracle.com/cd/E11882_01/server.112/e41573/sql_tune.htm#PFGRF95159

17.5.1 Overview of SQL Profiles

A SQL profile contains corrections for poor optimizer estimates discovered during Automatic SQL Tuning. This information can improve optimizer cardinality and selectivity estimates, which in turn leads the optimizer to select better plans.

The SQL profile does not contain information about individual execution plans. Rather, the optimizer has the following sources of information when choosing plans:

• The environment, which contains the database configuration, bind variable values, optimizer statistics, data set, and so on

• The supplemental statistics in the SQL profile

If the environment or SQL profile change, then the optimizer can create a new plan.

You can use SQL profiles with or without SQL plan management. If you use SQL plan management, then the plan chosen by the optimizer must be an enabled plan baseline. If the statement has multiple plans in the baseline, then the profile remains useful because it enables the optimizer to chose the lowest-cost plan in the baseline.