Characteristics of the database system: 1. Overall data structure, that is, any data in the database does not belong to any application, the data is public, and the structure is comprehensive; 2. Data sharing is high; 3. High data independence; 4. High degree of data control capabilities.
The operating environment of this tutorial: windows7 system, mysql8 version, Dell G3 computer.
Database System is a system composed of database and its management software.
The database system is an ideal data processing system developed to meet the needs of data processing. It is also a software system that provides data for actual operable storage, maintenance and application systems. It is a storage medium. , a collection of processing objects and management systems.
Characteristics of the database system
1. Overall data structure
Any information in the database None of the data belongs 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 the data is displayed, the logical structure of the data can be displayed at the same time; the entire The overall data of the organization is considered comprehensively and the overall data is structured. 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
higher security
better Data integrity
Strong concurrency control capability
Strong data recovery capability
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