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数据管理（外文文献翻译）,1.why data management?we have already considered hardware and software in some detail. in this chapter, we turn our attention to a third basic computer resource...
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1.Why Data Management?
We have already considered hardware and software in some detail. In this chapter, we turn our attention to a third basic computer resource, data. Many computer applications require that data be stored for subsequent processing. [1] Simply storing the data is not enough, however. A typical computer system, even a small one, can have dozens of disks and taped, each holding data for dozens of different applications. For any given application, one and only one set of data will do. We must be able to store, locate, and retrieve the specific data needed by a given program. That is the concern of data management.
2.Accessing Data
Imagine a single diskette containing several programs. For a particular application, only one of those programs will do. How is a given program selected, loaded, and executed? We learned that the operating system, responding to a user’s command, reds the disk’s index, searches it for the requested program name, extracts the program’s track and sector address, and issues primitive commands to read it into main memory. Later, following a RUN command, the program is given control of the processor.
1.为什么要数据管理
许多计算机应用要求数据存放起来，以备后用，然而简单地存放数据是不够的。一个普通的计算机系统，甚至一个小系统，可有几十个磁盘和磁带，每一个都为几十个不同的应用保存数据，对任意给定的应用，只用到一组数据就够了，必须能存储、定位和检索一个给的程序所需要的特定数据，这就是为什么需要数据管理的原因。
2.存取数据
设想一个含有若干程序的软盘，对于一个特定的应用，这些程序中只有一个要工作。如何选定、装入和招待这个程序呢？我们知道操作系统响应用户的命令，读出磁盘的索引，根据所要求的程序名字查找程序，得到了存放程序的磁道和扇区的地址，并发出原始命令，把程序从磁盘读到主存中，接着，在RUN命令之后，处理器就招待该程序了。
We have already considered hardware and software in some detail. In this chapter, we turn our attention to a third basic computer resource, data. Many computer applications require that data be stored for subsequent processing. [1] Simply storing the data is not enough, however. A typical computer system, even a small one, can have dozens of disks and taped, each holding data for dozens of different applications. For any given application, one and only one set of data will do. We must be able to store, locate, and retrieve the specific data needed by a given program. That is the concern of data management.
2.Accessing Data
Imagine a single diskette containing several programs. For a particular application, only one of those programs will do. How is a given program selected, loaded, and executed? We learned that the operating system, responding to a user’s command, reds the disk’s index, searches it for the requested program name, extracts the program’s track and sector address, and issues primitive commands to read it into main memory. Later, following a RUN command, the program is given control of the processor.
1.为什么要数据管理
许多计算机应用要求数据存放起来，以备后用，然而简单地存放数据是不够的。一个普通的计算机系统，甚至一个小系统，可有几十个磁盘和磁带，每一个都为几十个不同的应用保存数据，对任意给定的应用，只用到一组数据就够了，必须能存储、定位和检索一个给的程序所需要的特定数据，这就是为什么需要数据管理的原因。
2.存取数据
设想一个含有若干程序的软盘，对于一个特定的应用，这些程序中只有一个要工作。如何选定、装入和招待这个程序呢？我们知道操作系统响应用户的命令，读出磁盘的索引，根据所要求的程序名字查找程序，得到了存放程序的磁道和扇区的地址，并发出原始命令，把程序从磁盘读到主存中，接着，在RUN命令之后，处理器就招待该程序了。
