Oracle 1Z0-117 問題集

質問 1：
Refer to the Exhibit.

Execution plan:

What must be the correct order of steps that the optimizer executes based on the ID column the execution plan?
A. 3, 5, 4, 7, 6
B. 4, 5, 3, 7, 6
C. 3, 4, 5, 7, 6
D. 3, 5, 4, 6, 7
正解：B

質問 2：
Examine the Exhibit 1 to view the structure of and indexes for EMPLOYEES and DEPARTMENTS tables.


Which three statements are true regarding the execution plan?
A. The in-line query in the select list is processed as a view and then joined.
B. The view operator collects all rows from a query block before they can be processed but higher operations in the plan.
C. The optimizer pushes the equality predicate into the view to satisfy the join condition.
D. The optimizer chooses sort-merge join as a join method because an equality predicate is used for joining the tables.
E. The optimizer chooses sort-merge join because sorting is required for the join equality predicate.
正解：A,B,C
解説: (Topexam メンバーにのみ表示されます)

質問 3：
An application user complains about statement execution taking longer than usual. You find that the query uses a bind variable in the WHERE clause as follows:

You want to view the execution plan of the query that takes into account the value in the bind variable PCAT.
Which two methods can you use to view the required execution plan?
A. Use the DBMS_XPLAN.DISPLAY function to view the execution plan.
B. Execute the statement with different bind values and set AUTOTRACE enabled for session.
C. View the execution plan for the statement from V$SQL_PLAN.
D. Identify the SQL_ID for the statement and fetch the execution plan PLAN_TABLE.
E. Identify the SQL_ID for the statementsand use DBMS_XPLAN.DISPLAY_CURSOR for that SQL_ID to view the execution plan.
正解：C,E
解説: (Topexam メンバーにのみ表示されます)

質問 4：
Which two statements are true about the use of the DYNAMIC_SAMPLING hint in a query?
A. It is always used for flashback queries that contain the AS OF clause.
B. It estimates selectivity better for the filters.
C. It cannot be used if there is a single-table predicate in the WHERE clause.
D. It can compensate for the lack of extended statistics to get accurate cardinality estimates for complex predicate expressions.
E. It cannot be used for processing SQL statements in parallel.
正解：D,E
解説: (Topexam メンバーにのみ表示されます)

質問 5：
Which two types of SQL statements will benefit from dynamic sampling?
A. Short-running SQL statements
B. SQL statements that are resource-intensive and have the current statistics
C. SQL statements that are executed parallel
D. SQL statement that use a complex predicate expression when extended statistics are not available.
E. SQL statements with highly selective filters on column that has missing index statistics
正解：C,D
解説: (Topexam メンバーにのみ表示されます)