Which two recommendations can you get?

You are administering a database supporting an OLTP workload. A new module was added to one
of the applications recently in which you notice that the SQL statements are highly resource
intensive in terms of CPU, I/O and temporary space. You created a SQL Tuning Set (STS)
containing all resource-intensive SQL statements. You want to analyze the entire workload
captured in the STS. You plan to run the STS through the SQL Advisor.
Which two recommendations can you get?

A.
Combing similar indexes into a single index

B.
Implementing SQL profiles for the statements

C.
Syntactic and semantic restructuring of SQL statements

D.
Dropping unused or invalid index.

E.
Creating invisible indexes for the workload

F.
Creating composite indexes for the workload

Explanation:
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 , creation of new indexes (F),
restructuring of the SQL statement (C), or creation of a SQL profile. You can choose to accept the
recommendation to complete the tuning of the SQL statements.
Reference: Oracle Database Performance Tuning Guide 11g , SQL Tuning Advisor