OCP-1Z0-053-V12.02-40题

40.Evaluate the following code:
SQL>VARIABLE task_name VARCHAR2(255);
SQL>VARIABLE sql_stmt VARCHAR2(4000);
SQL>BEGIN :sql_stmt := 'SELECT COUNT(*) FROM customers WHERE cust_state_province =''CA''';
:task_name := 'MY_QUICKTUNE_TASK';
DBMS_ADVISOR.QUICK_TUNE(DBMS_ADVISOR.SQLACCESS_ADVISOR,
:task_name, :sql_stmt);
END;
What is the outcome of this block of code?
A. It creates a task and workload, and executes the task.
B. It creates a task and workload but does not execute the task.
C. It produces an error because a template has not been created.
D. It produces an error because the SQL Tuning Set has not been created.
Answer: A
答案解析：
参考：http://docs.oracle.com/cd/E11882_01/server.112/e41573/advisor.htm#PFGRF94911

Performing a Quick Tune

To tune a single SQL statement, the

QUICK_TUNE

procedure accepts as its input a

task_name

and a SQL statement. The procedure creates a task and workload and executes
this task. There is no difference in the results from using

QUICK_TUNE

. They are exactly the same as those from using

EXECUTE_TASK

,
but this approach is easier to use when there is only a single SQL statement to be tuned. The syntax is as follows:

DBMS_ADVISOR.QUICK_TUNE (
advisor_name IN VARCHAR2,
task_name IN VARCHAR2,
attr1 IN CLOB,
attr2 IN VARCHAR2 := NULL,
attr3 IN NUMBER := NULL,
task_or_template IN VARCHAR2 := NULL);

The following example shows how to quick tune a single SQL statement:

VARIABLE task_name VARCHAR2(255);
VARIABLE sql_stmt VARCHAR2(4000);
EXECUTE :sql_stmt := 'SELECT COUNT(*) FROM customers
WHERE cust_state_province =''CA''';
EXECUTE :task_name := 'MY_QUICKTUNE_TASK';
EXECUTE DBMS_ADVISOR.QUICK_TUNE(DBMS_ADVISOR.SQLACCESS_ADVISOR,
:task_name, :sql_stmt);