What are the main features of the database system?

1. data structuring

2. The data * * * is interesting, low redundancy and easy to expand.

3. High data independence

4. The data is managed and controlled by the database management system.

The database system realizes the structure of the whole data, which is one of the most important characteristics of the database. The "whole" structure mentioned here means that the data in the database is not only for an application, but for the whole organization; Data is not only internally structured, but also integrally structured, and there is a connection between the data. Because data is integral, it can be used by multiple users and applications, which can greatly reduce data redundancy, save storage space and avoid incompatibility and inconsistency between data.

High data independence

Data independence includes physical independence and logical independence of data.

Physical independence refers to how data is stored in the database on disk, which is managed by DBMS. The user program does not need to know, and the application program only needs to deal with the logical structure of the data, so that when the physical storage structure of the data changes, the user program does not need to change.

Logical independence means that the logical structure of user's application program and database is independent of each other, that is, if the logical structure of data changes, the user's program may not change.

The independence of data and program separates the definition of data from the program, and DBMS is responsible for providing access to data, thus simplifying the writing of application programs and greatly reducing the maintenance and modification of application programs. [ 1]

The data is managed and controlled by the database management system.

The enjoyment of the database is concurrent, that is, multiple users can access the data in the database at the same time, or even the same data in the database at the same time.

The DBMS must provide the following data control functions:

Data security (security)

Data integrity check (integrity)

Concurrency of database access control.

Database fault recovery (recovery)