2. 计算机
  3. A transaction is an action，or a series of actions，carried out by a single user or (71)________________，that accesses or changes

A transaction is an action，or a series of actions，carried out by a single user or (71)________________，that accesses or changes

admin2020-04-30  43
问题     A transaction is an action，or a series of actions，carried out by a single user or  (71)________________，that accesses or changes the contents of the database．
    A transaction should possess the four basic or so-called ACID properties：
    Atomicity．The“all or nothing”property．A transaction is an (72)________________ unit that is either  performed in its entirety or is not performed at all．
    Consistency．A transaction must transform the database from one consistent state to another consistent state．
    Isolation．Transactions execute independently of one another．In other words，the partial effects of  (73)________________ transactions should not be visible to other transactions．
    Durability．The effects of a successfully completed(committed)transaction are permanently recorded in the database and must not be lost because of a subsequent failure．
    The four properties above，only (74)________________ property is the responsibility of the concurrency  control subsystem to ensure．It is the responsibility of both the (75)________________ and the application  developers to ensure consistency．To guarantee the Atomicity and Durability properties after a  failure，a log file is needed．
选项 A、application developer
B、all users
C、application program
D、DBMS
答案C
解析
转载请注明原文地址:https://kaotiyun.com/show/yfTZ777K
本试题收录于： 数据库系统工程师上午基础知识考试题库软考中级分类
0

数据库系统工程师上午基础知识考试

软考中级

相关试题推荐
随机试题
最新回复(0)