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This article is to share with you what is the component of the database system, Xiaobian feels quite practical, so share it with you to learn, I hope you can gain something after reading this article, not much to say, follow Xiaobian to have a look.

As we all know, database system consists of four parts: data, hardware, software and users. So what are the concepts of these four parts and what are their responsibilities?

Let's talk about the four main parts of a database system:

1. data

Database systems can be used on computers ranging from personal computers to mainframes. Obviously, the functionality that any system can provide depends to some extent on the size and capabilities of the machine on which it operates. In particular, systems on mainframes ("large systems") tend to be multi-user, while systems on minicomputers ("small systems" ) tend to be single-user. A single-user system has at most one user accessing the database system at any one time. A multi-user system can have multiple users accessing the database system simultaneously. For the sake of generality, this book assumes the latter system, but in practice this distinction is irrelevant to most users, since the main purpose of a typical multiuser system is to make each user feel as if he or she is operating on a single-user system. Problems with multi-user systems are primarily internal to the system, not those visible to users

2. hardware

The hardware part of the system includes secondary storage devices, as well as related I / O devices (disk drives, etc.), device controllers, I / O channels, etc. Secondary storage devices (mostly disks) are used to store data. Hardware processor and corresponding main memory. Hardware processors and corresponding main memory are used to support the execution of database system software.

3. software

Between the physical database (e.g., physically stored data) and the users of the database system is a layer, the software layer, commonly referred to as the database manager or database server, and most commonly referred to as the database management system (DBMS). All requests to access the database are handled by DBMS. DBMS provides many utilities for manipulating data. DBMS provides basic functionality that masks physical layer details from database users (just as programming language systems mask physical layer details from application programmers). In other words, DBMS provides users with a high-level way to view databases above the hardware layer, and enables users to express operational requests in this high-level way.

4. user

Let's consider three broad categories of primary users (which may overlap somewhat): first, application programmers. Application programmers are responsible for writing database applications. They write applications in programming languages such as C O B O L, P L / I, C++, Java, or some high-level fourth-generation language. These programs access databases by issuing SQL statement requests to DBMS. These programs can usually be batch applications or online applications designed to allow end-users to access databases through online workstations or terminals. Most of today's applications are online.

The second category of users are end users. They interact with the system from online workstations or terminals. The end user may access the database through the online application mentioned in the preceding paragraph, or he or she may use the interface provided by the database system software.

The third type of user is the database administrator or DB A for short.

The above is what the components of the database system are. Xiaobian believes that some knowledge points may be seen or used in our daily work. I hope you can learn more from this article. For more details, please follow the industry information channel.

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