1. Realize data sharing: Data sharing includes that all users can access the data in the database at the same time, and users can use the database in various ways through the interface and provide data sharing.

2. Reduce data redundancy: Compared with the file system, because the database realizes data sharing, users are prevented from creating application files independently. Reduce a large number of duplicate data, reduce data redundancy and maintain data consistency.

3. Maintain data independence: data independence includes logical independence (the logical structure of database and application is independent of each other) and physical independence (the change of physical structure of data does not affect the logical structure of data).

4. Centralized control of data: In the file management mode, the data is in a decentralized state, and different users or the same user do nothing with their own files in different processes. Database can be used to centrally control and manage data, and data model can be used to express the organization of various data and the relationship between data.

5. Consistency and maintainability of data, ensuring the security and reliability of data: mainly including security control, integrity control and concurrency control, allowing multiple accesses to data in the same time period to prevent abnormal interaction between users.

6. Fault recovery: The database management system provides a set of methods to find and repair faults in time, thus preventing data from being destroyed. The database system can recover the faults occurred during the operation of the database system as soon as possible, which may be physical or logical errors. Such as data errors caused by system misoperation.

Extended data

Application and characteristics of database technology

Database was originally used as the basis for large-scale transaction processing by large companies or institutions. Later, with the popularity of personal computers, database technology was transplanted to PC (PersonalComputer) for single-user personal database applications. Then, because the PC is networked in the workgroup, the database technology is transplanted to the workgroup level.

Nowadays, databases are widely used in Internet and Intranet. In the mid-1960s, database technology was used to solve the problem of file processing system. At that time, the database processing technology was still very fragile, and it was often impossible to submit applications. The birth of relational model in 1970s provided a standard method for database experts to construct and process databases, and promoted the development and application of relational databases.

1979, Ashton-Tate company introduced the microcomputer product dBase, and called it the relational database management system. Since then, database technology has been transplanted to personal computers. From the mid-1980s to the late 1980s, end users began to use local area network technology to connect independent computers into a network, and terminals shared databases, thus forming a new multi-user data processing mode, called client/server database structure.

Now, database technology is being combined with Internet technology to publish database data on intranet, departmental local area network and even the World Wide Web.

—database