One of the database design series

First come to know what is the database design?

What do you want to explain here about the DBMS?

Database Management System is a large-scale software that manipulates and manages databases, and is used to establish, use, and maintain databases, referred to as DBMS. It unifies the database management and the control, guarantees the database security and the integrity, the user accesses the data in the database through the DBMS, the database administrator also carries on the database maintenance work through the DBMS, it provides the many functions, may enable many applications and the user to use the different method at the same time or different time to establish, Modify and access the database.

When looking for a book, the librarian first finds the book's Classification number and ISBN by the directory search, and then finds that kind of bookshelf in the library, and finds it on which shelf according to the order of the number, so that we can quickly find the books we need, and the data in the database is like the books in the library. It also makes it easy for people to find it.

If all the books are put together in an irregular, random pile anywhere, then the people who borrow books, hehe, he will never borrow books. It's rather vulgar here, don't mind. The same reasoning that the data are stacked up like this, so that people can not find, then this data collection can not be called a database.

Database management system is improved from the management of the library, 21st century, too much information, too many messages, we all go to the computer, which leads to more and more information in the computer, this time the emergence of database management system to solve the problem of managing these materials, It is managed through a number of well-developed computer programs that, as the name implies, can help us manage the large amounts of data entered into the computer, like librarians.

According to the function, the database management system can be broadly divided into 6 parts:

(1) Mode translation: Provides data definition language (DDL). The database schema written with it is translated into an internal representation. The logical structure, integrity constraints, and physical storage structure of the database are stored in the internal data dictionary. Database schema is the basis for various data operations (such as Find, modify, insert, delete, etc.) and maintenance management of database.

(2) Application compilation: Compiles the application that contains the Access database statements into a target program that can be run under DBMS support.

(3) Interactive query: Provides easy-to-use interactive query language, such as SQL. The DBMS is responsible for executing the query commands and displaying the query results on the screen.

(4) organization and access of data: provide the physical organization and access method of data on peripheral storage devices.

(5) Transaction operation Management: Provide transaction operation Management and operation log, transaction operation security Monitoring and data integrity check, transaction concurrency control and system recovery 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.

The database management system based on the relational model has been perfected, and it is widely used as a commodity software in all walks of life, it is applied in the distributed multi-user environment of each server structure, and the application of database system is further expanded. With the development of new data model and data management technology, it is expected that the performance of DBMS software will be updated and perfected, and the application field will be further broadened.

Database management System (DBMS) is a new subject which has developed rapidly in recent more than 10 years in order to adapt to the demand of data management technology in information society. 　　Computer data management technology has undergone three stages of development: the free Management phase the user organizes the data in file form and is attached to the respective application. 　　The file system in the file management phase of the operating system gives a unified file structure and common access method, the user can keep the data and information as a file for long-term storage in the computer system, and can easily query and processing. 　　In order to adapt to the centralized storage of large amount of data, and to provide the requirements for multiple users to share, the data and program are completely independent, minimizing the redundancy of the data, and the database management system appears. 　　Famous database management system MS SQL SYBASE DB2 ORACLE MySQL ACCESS VF It provides the following features: (1), data definition function. 　　(2), data management functions. 　　(3), to protect the database. 　　(4), the establishment and maintenance of the database. (5), the transmission of the database.

One of the database design series