You want to analyze a SQL Tuning Set （STS） using SQL Performance Analyzer in a test database. Which two statements are true regarding the activities performed during the test execution of SQLs in a SQL Tuning Set？（）

A

 Every SQL statement in the STS is considered only once for execution.

B

 The SQL statements in the STS are executed concurrently to produce the execution plan and execution statistics.

C

 The execution plan and execution statistics are computed for each SQL statement in the STS. 

D

 The effects of DDL and DML are considered to produce the execution plan and execution statistics.