What is the core and foundation of a database system?
The core and foundation of the database system is the "data model". Computers cannot directly process objective things in the real world, and database systems use computer technology to manage objective things. Therefore, it is necessary to abstract and simulate objective things to establish a data model suitable for database system management. The data model describes the static characteristics, dynamic behavior and constraints of the system from an abstract level, providing an abstract framework for the information representation and operation of the database system.
The operating environment of this tutorial: Windows 7 system, 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.
The core and foundation of the database system is the data model. All existing database systems are based on some kind of data model.
Data Model is an abstraction of data characteristics. It describes the static characteristics, dynamic behavior and constraints of the system from an abstract level, and provides an abstract framework for the information representation and operation of the database system. The content described by the data model has three parts, namely data structure, data operations and data constraints.
Computers cannot directly process objective things in the real world, and database systems use computer technology to manage objective things. Therefore, it is necessary to abstract and simulate objective things in order to establish a database system suitable for management. data model. A data model is a simulation and abstraction of real-world data characteristics.
The data model is a tool used in database design to abstract the real world. It is a formal framework used in the database to provide information representation and operation methods.
The content described by the data model includes three parts: data structure, data operations, and data constraints
Data structure: in the data model Data structure mainly describes the type, content, nature of data and the relationship between data. Data structure is the basis of data model, and data operations and constraints are based on data structure. Different data structures have different operations and constraints.
Data operations: Data operations in the data model mainly describe the types and methods of operations on the corresponding data structures.
Data constraints: Data constraints in the data model mainly describe the syntax and semantic connections between data in the data structure, the constraints and dependencies between them, and the rules for dynamic changes in the data. To ensure that the data is correct, valid and consistent.
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