多项选择题
Which three statements are true regarding subqueries?（）
A.Subqueries can contain GROUP BY and ORDER BY clauses
B.Main query and subquery can get data from different tables
C.Main query and subquery must get data from the same tables
D.Subqueries can contain ORDER BY but not the GROUP BY clause
E.Only one column or expression can be compared between the main query and subquery
F. Multiple columns or expressions can be compared between the main query and subquery
相关考题
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多项选择题
Which DBMS_SCHEDULER procedure(s) can be used to alter an existing job? （）
A. SET_ATTRIBUTE_NULL
B. ALTER_JOB
C. ALTER_JOB_PARAMETERS
D. ALTER
E. SET_ATTRIBUTE -
多项选择题
Which Scheduler view(s) can be queried to see which jobs are currently executing? （）
A. DBA_SCHEDULER_JOB_RUN_DETAILS
B. DBA_SCHEDULER_RUNNING_JOBS DBA
C. DBA_SCHEDULER_CURRENT_JOBS
D. DBA_SCHEDULER_JOBS DBA
E. DBA_SCHEDULER_EXECUTING_JOBS -
单项选择题
Whichstatementistrueregardingsynonyms?（）
A.Synonyms can be created only for a table
B.Synonyms are used to reference only those tables that are owned by another user
C.A public synonym and a private synonym can exist with the same name for the same table
D.The DROP SYNONYM statement removes the synonym, and the table on which the synonym has been created becomes invalid
