单项选择题

The EMPLOYEES table has six indexes and DML operations are slow. Which command begins monitoring the EMPLOYEE_IDX_FK index to determine whether it has been used by an execution plan？（）

A.ALTER TABLE employees monitor index employee_idx_fk;
B.ALTER INDEX employee_idx_fk monitoring on;
C.ALTER TABLE employees monitor all indexes;
D.ALTER INDEX employee_idx_fk monitoring usage;

点击查看答案&解析

上一题目录下一题

相关考题

多项选择题

Using a bitmap structure to manage database object space has several benefits over using freelist structures. Which three are benefits of managing space using automatic-segment-space managed objects？（）

A.It readily responds to dynamic changes for concurrent access.
B.It improves performance and space utilization in a multiple-instance environment.
C.It requires fewer space related options then freelist managed structures.
D.It improves performance for SYSTEM tablespaces where a high degree of concurrency is required.

单项选择题

When does Oracle9i flag an index as being used in the V$OBJECT_USAGE view？（）

A.During a query’s parse time only.
B.During a query’s execution time only.
C.During any kind of DML statement execution.
D.During the execution of an INSERT statement only.

多项选择题

Which two are true regarding external tables？（）

A.External tables can be updated.
B.External tables are read-only tables.
C.Indexes can be created on external tables.
D.Indexes cannot be created on external tables.