The （74） scheme in a database system is responsible for the detection of failures and for the restoration of the database to a state that existed before the occurrence of the failure.

（74）

A． query

B． test

C． check

D． recovery

[单选题]The______scheme in a database system is responsible for the detection of failures and for the restoration of the database to a state that existed before the occurrence of the failure．A．queryB．testC．checkD．RecoveryA．B．C．D．

[单选题]An operating system is (74) .(74) A． the highest layer of softwareB． the lowest layer of softwareC． the highest layer of hardwareD． the lowest layer of hardware

I suggest we put the scheme into effect, for it is quite _________.A. eligibleB.

[单选题]A． complete computer system contains(74)。A．arithmetic unit, control unit and memoryB．input/output devices and mainframeC．mainframe. and programs of utilityD．hardware system and software system

以下不是数据库管理系统(Database Management System，DBMS)功能的是:A. 建立和维护数据库B. 作为操作系统的一部分,管理文件的存

[主观题]Why we use index in database? How many indexes is the maximum in onetable as your suggestion?

[单选题]Oil pressure in the lubrication system is （） the static sea water head to ensure that sea water （） the stem-tube.A . lower than；can lubricateB . lower than；can coolC . higher than；can enterD . higher than ；cannot enter

[单选题]( )，may I have a question on the control system presentation？A.I’m sorryB.T

[单选题] The user must interact with the (74) in order to accomplish task.(74)A． printerB． memoryC． CPUD． operating system

[单选题]C3I system for Air Defense 即为防空C3I系统，下列哪一项不是其中之一：（）A .指挥B .控制C .通信D .侦察