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;
相关考题
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多项选择题
Usingabitmapstructuretomanagedatabaseobjectspacehasseveralbenefitsoverusingfreeliststructures.Whichthreearebenefitsofmanagingspaceusingautomatic-segment-spacemanagedobjects？（）
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
WhendoesOracle9iflaganindexasbeingusedintheV$OBJECT_USAGEview？（）
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
Whichtwoaretrueregardingexternaltables？（）
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.
