本文共 2405 字，大约阅读时间需要 8 分钟。
Oracle OCP 1Z0-050（26题）解析
QUESTION 26:
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.SQL ACCESS_ADVISOR, :task_name, :sql_stmt);
END;
What is the outcome of this block of code?
A. It creates a task and workload but does not execute the task.
B. It produces an error because the SQL Tuning Set has not been created.
C. It produces an error because a template has not been created.
D. It creates a task and workload, and executes the task.
Answer: D
解析：
参考Oracle官方文档：
Using SQL Access Advisor in Enterprise Manager or API, you can do the following:
-
Recommend materialized views and indexes based on collected, user-supplied, or hypothetical workload information.
-
Recommend partitioning of tables, indexes, and materialized views.
-
Mark, update, and remove recommendations.
In addition, you can use SQL Access Advisor API to do the following:
-
Perform a quick tune using a single SQL statement.
-
Show how to make a materialized view fast refreshable.
-
Show how to change a materialized view so that general query rewrite is possible.
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);
See for more information regarding the QUICK_TUNE procedure and its parameters.