Basic Database knowledge

With the development of technology,DatabaseA great leap has also been made, and the technology is becoming more and more advanced. However, despite this, database knowledge still needs to be mastered by every user who learns the database, the following sections will provide you with detailed databaseBasic knowledgeFor your reference. Database) is a data warehouse that organizes, stores, and manages data according to the data structure. It was born fifty years ago. With the development of information technology and the market, especially after 1990s, data management is no longer just about data storage and management, but also the various data management methods required by users. There are many types of databases. From the simplest storage of tables with various types of data to the large database systems capable of storing massive data, they have been widely used in various aspects.

Definition 1

Strictly speaking, databases are "warehouses that organize, store, and manage data according to the data structure ". In the daily work of economic management, it is often necessary to put some related data into such a "warehouse" and handle the data according to the management needs. For example, an enterprise or a public institution's Personnel Department often stores the basic information of its employees (employee ID, name, age, gender, nationality, salary, and resume) in the table, this table can be viewed as a database. With this "Data Warehouse", we can query the basic information of a certain employee at any time as needed, as well as the number of employees with a certain wage range. If all these tasks can be performed automatically on the computer, then our personnel management can reach an extremely high level. In addition, a large number of such databases need to be established in financial management, warehouse management, and production management so that they can use computers to achieve automatic management of finance, warehouses, and production.

J. martin gave a complete definition to the database: the database is a collection of related data stored together. The data is structured and has no harmful or unnecessary redundancy, it also serves a variety of applications. Data Storage is independent of programs that use it. New data is inserted into the database, and the original data can be modified and retrieved in a public and controllable manner. When a system contains several fully separated databases, the system contains a "database set ".

Definition 2

A database is a set of data that is organized according to a certain data model and stored in the second-level memory. This type of data set has the following features: it serves as many applications as possible in the best way as possible for a specific organization. Its data structure is independent of its application, the unified software manages and controls the addition, deletion, modification, and retrieval of data. From the development history, the database is an advanced stage of data management, which is developed by the file management system.

Definition 3

(Opinion of the expert committee of the Berne Protocol)

All the compilation of information (data rate files), whether in the form of printing, computer storage unit, or other forms, should be considered as a "Database ".

There are many reasons for digital content selection, which are summarized as follows:

(1) storage space reasons. Digital products are accessed and used by users through the network. As we all know, digital products are stored on disk arrays. disk arrays are managed by servers, and disk space is limited, the capabilities of the server are limited, and it is impossible to store digital resources in an infinitely limited manner. This requires us to select the digital content of document resources.

(2) Resolving the contradiction between high cost of digital production and limited library funds. Almost no library has enough resources to digitize the entire collection, and the choice of content is inevitable.

(3) digital resource management needs. The rapid development of technology has shortened the life cycle of digital resources generated by digital projects. investing heavily in digital migration is an important way to prolong the life of digital resources, for expensive maintenance costs, you must consider digital content options.

Database development history database technology has formed a solid theoretical foundation, mature commercial products and a wide range of application fields in less than half a century since its birth, attract more and more researchers. The birth and development of databases have brought about a huge revolution in computer information management. Over the past 30 years, thousands of databases have been developed and built at home and abroad. It has become an infrastructure for enterprises, departments, and even individuals to work, produce, and live. At the same time, with the expansion and deepening of applications, the number and scale of databases are growing, and the research field of databases has been extended and deepened. In the past 30 years, the database field has won three computer Turing awards C. w. bachman, E. f. codd, J. gray), which fully demonstrates that the database is a dynamic and innovative field. Let's trace the history of the database.

Traditionally, in order to ensure the stable operation of an enterprise's ever-expanding IT system, the user information center usually not only constantly updates larger it o & M hardware and software devices, but also wastes enterprise resources; it is also necessary to maintain an O & M army consisting of various maintenance personnel such as database maintenance, server maintenance, and data center duty for a long time, and the maintenance costs will also increase. To this end, enterprise IT decision makers began to think: can they use it o & M services as needed? Instead of increasing the expensive O & M costs.

Definition 4

DataBase, DataBase) is a long-term data set that is stored in a computer, organized, shared, and centrally managed. She is a computer software system that stores and manages data in a data structure. The concept of a database actually involves two meanings:

1) A database is an entity. It is a "warehouse" that can properly store data. You can store the transaction data to be managed in this "warehouse, the concepts of "data" and "Database" are combined into databases.

2) The database is a new method and technology of data management. It can organize data more appropriately, maintain data more conveniently, control data more closely, and use data more effectively.

The basic knowledge about databases has been introduced to you so much that you will continue to learn more about the basic knowledge about databases in the future. If you want to learn the database well, first, you must master the basic knowledge of the database. I hope the Knowledge mentioned above will be helpful to everyone.