The database management system is a large-scale software that manipulates and manages databases. It is used to establish, use and maintain databases; it provides unified management and control of databases to ensure the security and integrity of the databases.
The operating environment of this article: Windows 7 system, Dell G3 computer.
What is a database management system?
Database management system is a large-scale software that manipulates and manages databases. It is used to establish, use and maintain databases; it provides unified management and control of databases to ensure the security and integrity of the databases. sex.
Users access data in the database through DBMS (database management system), and database administrators also perform database maintenance through DBMS. It can support multiple applications and users using different methods to create, modify and query the database at the same time or at different times. Most DBMS provide data definition language DDL (Data Definition Language) and data manipulation language DML (Data Manipulation Language) for users to define the schema structure and permission constraints of the database and implement operations such as appending and deleting data.
According to functions, the database management system can be roughly divided into 6 parts:
(1) Schema translation:
Provides data definition language ( ddl). Database schemas written in it are translated into internal representations. The logical structure, integrity constraints and physical storage structure of the database are stored in the internal data dictionary. Various data operations of the database (such as search, modification, insertion and deletion, etc.) and database maintenance and management are based on the database schema.
(2) Compilation of application programs:
Compile the application program containing the statements to access the database into a target program that can be run with the support of dbms.
(3) Interactive query:
Provides an easy-to-use interactive query language, such as SQL. DBMS is responsible for executing query commands and displaying query results on the screen.
(4) Data organization and access:
Provide the physical organization and access methods of data on peripheral storage devices.
(5) Transaction operation management:
Provides transaction operation management and operation logs, transaction operation security monitoring and data integrity check, transaction concurrency control and system recovery and other functions.
(6) Database maintenance:
Provide software support for database administrators, including maintenance tools such as data security control, integrity assurance, database backup, database reorganization, and performance monitoring.
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