4 characteristics of database

The four characteristics of the database are: 1. Overall data structure; 2. High degree of data sharing; 3. High data independence; 4. High degree of data control capabilities. Database system refers to the system structure after introducing a database into the computer system.

#The operating environment of this article: windows10 system, thinkpad t480 computer.

Database system (DateBase System, referred to as DBS) refers to the system after introducing a database into the computer system. It consists of computer hardware, operating system, DBMS, DB, applications and users, as well as database development and management personnel. composition.

DBS has the following four main features:

1. Overall data structure

Any data in the database does not belong to any application. The data is public and the structure is comprehensive. In a database, the number of data files is limited and fixed, but the applications of the database system are unlimited.

Benefits: The structuring of the overall data can reduce or even eliminate unnecessary data redundancy, thus saving the storage space of the overall data and avoiding data inconsistency and incompatibility (the data does not meet the regulations) Restrictions).

2. High degree of data sharing

The data and the logical structure of the data are stored in the database at the same time. When displaying the data, the logical structure of the data can be displayed at the same time; the overall data of the entire organization is integrated Consider,the overall data structure. Therefore, DBS has a high degree of data sharing.

Benefits: Legal users can easily access and use the data in the database without worrying about data inconsistency and incompatibility. The data in the database can adapt to the reasonable requirements of various legal users and the requirements of various applications, and can easily expand new applications.

3. High data independence

Data independence refers to the correlation between data and applications. The data and data structure are stored in the database (on external memory) and managed by the DBMS. The application stores neither the data nor the logical structure of the data.

Physical independence: When the storage method of data in the database changes, the DBMS can appropriately change the way of converting the data, so that the logical structure of the data faced by users remains unchanged, so that the applications that process the data also remain unchanged. Change.

Logical independence: When the logical structure of the data in the database changes, the DBMS can appropriately change the data conversion method, and the logical structure of the data faced by the user remains unchanged.

Benefits: Data and programs are independent of each other, making it easy to compile various applications and greatly reducing application maintenance work.

4. High degree of data control capability

a, higher security

b, better data integrity

c, stronger The concurrency control capability

d, strong data recovery capability

The above-mentioned DBMS functions ensure the normal operation of the database and greatly simplify the application program.

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