What is a database system? What is the difference between a database and an information base?
Conceptually, data is not equal to information. Information is often represented by data, and information is meaningful only after processing, and only then can there be some form of data. For example, meteorological engineers use various instruments to record data such as wind direction, wind speed, rainfall, temperature and humidity. And then draw it into a meteorological cloud map to obtain meteorological information, so as to make weather forecasts such as sunny or cloudy. Data represents information. In a computer, information is a set of numbers, letters or symbols that can be processed by the computer.
From the organizational form, database and information base also have different characteristics.
First of all, try not to duplicate the data stored in the database. For example, when banks handle deposits, loans and other businesses, they need to keep the customer's name and address on the documents. Suppose each department has a customer file, and the name and address of this customer will be stored three times. If the customer moves to another place, the customer's address will be modified in three files. If the customer database is established, the customer's name and address only need to be stored once, and only need to be modified once. Therefore, using the database method can reduce the repeated storage of data. But a lot of information in the database can be partially copied.
Secondly, the storage of data in the database is independent, so users don't have to know where and how to store the data when starting the application. These things are done automatically by the computer system. In this way, users can concentrate on designing good applications. For the information stored in the information base, users must clearly know where each device storing information is placed before they can access it.
Thirdly, the database for storing data must have a certain format, and the information stored in the information base does not need any format, only for various devices for storing information, such as films, pictures, disks, optical disks, etc. As long as these devices are intact, the authenticity and reliability of information can be guaranteed.
Learning point
Data compression technology
Data compression technology is a technology that uses the least number of bits to represent signals. In today's electronic information technology field, a far-reaching digital revolution is taking place. Because of the huge amount of digital multimedia information, especially digital video and audio signals, it is difficult to get practical application without effective compression. Therefore, data compression technology has become a key technology in digital communication, broadcasting, storage and multimedia entertainment.