多项选择题

Which two statements are true regarding views?（）

A.A subquery that defines a view cannot include the GROUP BY clause
B.A view that is created with the subquery having the DISTINCT keyword can be updated
C.A view that is created with the subquery having the pseudo column ROWNUM keyword cannot be updated
D.A data manipulation language (DML) operation can be performed on a view that is created with the subquery having all the NOT NULL columns of a table

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单项选择题

What is the default value for the ENABLED attribute of a job or program when it is created? （）

A. TRUE
B. FALSE
C. There is no default. It must be defined at creation time.
D.PENDING
E. NULL

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

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