多项选择题
A.Each segment contains one or more extents.
B.Multiple tablespaces can share a single data file
C.A data block is the smallest unit of input/output （I/O） in data files.
D.It is possible to have tablespaces of different block sizes in a database.
E.Each data block in the database always corresponds to one operating system block
多项选择题 Whichstatementsregardingtheserverparameterfile（SPFILE）aretrue（）
单项选择题 Which statement is true about loading data using the conventional path of SQL*Loader（）
多项选择题 User SCOTT executes the following command on the EMP table but has not issued COMMIT， ROLLBACK， orany data definition language （DDL） command： SQL> SELECT ename FROM emp WHERE job=’CLERK’ FOR UPDATE OF empno； SCOTT has opened another session to work with the database instance. Which three operations would waitwhen issued in SCOTT’s second session（）