Shulou(Shulou.com)06/03 Report--

In this issue, the editor will bring you about the characteristics of the relational database. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

The main characteristics of relational database: 1, data centralized control; 2, high data independence; 3, good data sharing; 4, small data redundancy; 5, data structure; 6, unified data protection function.

A relational database is a database based on a relational database model, which deals with the data in the database with the help of concepts and methods such as set algebra. at the same time, it is also a group of tables with formal description. The essence of this form of table is to load a special collection of data items. The data in these tables can be accessed or reconvened in many different ways without the need to reorganize database tables.

The definition of a relational database results in a table of metadata or a formal description of tables, columns, ranges, and constraints. Each table (sometimes referred to as a relationship) contains one or more types of data represented by columns. Each row contains a unique data entity, which is the category defined by the column.

When creating a relational database, you can define the range of possible values of a data column and further constraints that may be applied to that data value.

The SQL language is the interface between standard users and applications to relational databases. Its advantage is that it is easy to expand, and after the initial database creation, a new data type can be added without the need to modify all existing applications. The mainstream relational databases are oracle, db2, sqlserver, sybase, mysql and so on.

The main characteristics of Relational Database

1) centralized control of data. In the file management method, files are scattered, each user or each processing has its own files, these files are generally not related, therefore, can not be controlled, maintained and managed in a unified way. The database overcomes this shortcoming and can centrally control, maintain and manage the relevant data.

2) High data independence. The data in the database is independent of the application program, including the physical and logical independence of the data, which provides convenience for the use, adjustment, optimization and further expansion of the database, and improves the stability of the database application system.

3) data sharing is good. The data in the database can be used by multiple users, and each user is only connected with a part of the data in the database; the user data can overlap, and the user can access the data at the same time without affecting each other, which greatly improves the efficiency of the database.

4) the data redundancy is small. The data in the database is not application-oriented but system-oriented. Unified definition, organization and storage of data, centralized management, avoid unnecessary data redundancy, but also improve the consistency of data.

5) the data is structured, the whole database is formed according to a certain structural form, the data are related to each other within the record and between the record types, and users can access the data through different paths.

6) unified data protection function, in the case of multi-users sharing data resources, strictly check the data used by users, specify passwords or access rights to the database, and refuse illegal users to enter the database. To ensure data security, consistency and concurrency control.

These are the characteristics of the relational database shared by the editor. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

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