When we talk about a databasewe must differentiate between the database（71）whi..

2021年上半年上午试卷综合知识

第 75 题


章/节	计算机专业英语

When we talk about a database,we must differentiate between the database（71）,which is the logical design of the database,and the database（72）,which is a snapshot of the data in the database at a given instant in time.The concept of a relation corresponds to the programming-language notion of a variable,while the concept of a relation schema corresponds to the programming-language notion of type definition. In general,a relation schema consists of a list of（73）and their corresponding domains.The concept of a relation instance corresponds to the programming-language notion of a value of a（74）.The value of a given variable may change with time; similarly the contents of a relation instance may change with time as the relation is updated.In contrast,the（75）оf a relation does not generally change.

A. table

B. schema

C. instance

D. view

相关试题计算机专业英语

第74题

2016年上半年

In the fields of physical security and information security, access control is the selective restriction of access to a place or other resource. The a..

第71题

2012年上半年

At a basic level, cloud computing is simply a means of delivering IT resources as (71). Almost all IT resources can be delivered as a cloud service: a..

第73题

2018年上半年

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.
..

更多复习资料
请登录电脑版软考在线 www.rkpass.cn

京B2-20210865 | 京ICP备2020040059号-5