How Do I Become a Database Specialist?

Database technology is a core technology of information systems. It is a method of computer-aided data management. It studies how to organize and store data, and how to obtain and process data efficiently.

Database Technology

Database technology is a core technology of information systems. Is a computer

Database technology was born in the late 1960s and early 1970s. Its main purpose is to effectively manage and access a large number of data resources. Database technology has mainly studied how to store, use and manage data. For years, database technology and computers

From the late 1960s to the present, database technology has evolved for more than 30 years. In the course of more than 30 years, people have made brilliant achievements in the theoretical research and system development of database technology, and have begun to

Database technology involves many basic concepts, including: information, data, data processing, database,

Information technology (IT) is one of the most frequently used terms today. With the widespread application of computer technology in industry, agriculture and daily life, more and more individuals and enterprises have surpassed the world as themselves. One of the signs of the trend. Database technology is an important support in information technology. Without database technology, people will feel helpless in the vast information world.

Database technology is an important branch of computer science and technology. Since the mid-1950s, computer applications have expanded from scientific research departments to business management and government administration departments, and people have increasingly demanded data processing. In 1968, the world's first commercialized

Scale will grow towards both ends-bigger and bigger, smaller and smaller. The so-called large refers to the size of the enterprise-level database. In the first 10 years, most of the data stored in databases were measured on the basis of GB, and dozens of GB were already very large. Today, only the amount of data added by Guangdong Mobile every month has been measured in terabytes. Within 3 years, many enterprises have to store data at the petabyte level. The amount of data is getting larger and larger, and a larger database is needed for support. This is one of the development directions of the database. On the other hand, the database will become smaller and smaller. now,

Development mainstream of next-generation database technology

In view of the existing limitations of relational database technology, the theoretical world now has three main views:

Object-oriented database technology will become the mainstream of the development of next-generation database technology. Some scholars believe that existing relational databases cannot describe real-world entities, and the object-oriented data model absorbs the core of mature object-oriented programming methodologies. Concepts and basic ideas make it consistent with the general method of human understanding of the world, and more suitable for describing the real world. Some even predict that the future of databases will be an object-oriented era.

Object-oriented relational database technology Relational database is almost the standard of current database systems. Relational languages can be used for almost any database operation together with conventional languages. However, its concise modeling capabilities, limited data types, and data structure constraints in programming. Waiting has become a bottleneck for relational databases to function. Object-oriented method originates from programming language. It itself uses the real-world entity object as the basic element to describe the complex objective world, but it is not as flexible as a database. Therefore, some scholars believe that the organic combination of object-oriented modeling capabilities and the function of relational databases for research is a development direction of database technology.

Object-oriented database technology Object-oriented database has the advantage of being able to represent complex data models, but because there is no unified data model and formal theory, it lacks a strict data logic foundation. While the deductive database has a strong mathematical logic foundation, it can only deal with flat data types. Therefore, some scholars combined the two, and proposed a new database technology-deductive object-oriented database, and pointed out that this technology may become the mainstream of the development of next-generation database technology.

New direction of database technology development

Unstructured database is a new database theory based on Internet applications, which is proposed by some researchers in view of the limitations of relational database models that are too simple, inconvenient to express complex nesting needs, and limited data types. Supports repeated fields, sub-fields, and variable-length fields and implements variable-length data and repeated fields processing and variable-length storage management of data items. It handles continuous information (including full-text information) and non-structured information (duplicate data and variable length). Data) has advantages unmatched by traditional relational databases. But researchers believe that this kind of database technology will not completely replace the popular relational databases today, but their useful supplement.

Another trend in the development of database technology

Some scholars have pointed out that the combination of database and subject technology will create a series of new databases, such as distributed databases, parallel databases, knowledge bases, multimedia databases, etc. This will be an important development direction of database technology. Among them, many researchers have focused on multimedia databases and believe that the introduction of multimedia technology and visualization technology into multimedia databases will be a hot and difficult point in the development of future database technologies.

The two major directions of future database technology and market development. Data warehouse e-commerce scholars have analyzed the development direction and application requirements of various database vendors based on the analysis of the current expansion of database vendors. Evolving views in two directions. They pointed out that since the previous year, many industries such as telecommunications, finance, and taxation have gradually realized the huge economic benefits brought by data warehouse technology to the macro development of enterprises, and have successively established data warehouse systems. The vendors that provide large-scale data warehouse solutions in China are mainly Oracle, IBM, Sybase, CA, and Informix. The projects that have been successfully constructed and have recovered their investment mainly include China Merchants Bank System and Guoxin Securities System. At present, the research on data warehouse by scholars at home and abroad is continuing. At the same time, some scholars have aimed at the perspective of database technology and market development in the field of e-commerce. They believe that today's information systems are gradually required to establish an application framework in a customer-centric manner, so database applications are bound to require more extensive contact with customers. The Internet gives us a very convenient way to connect. Through the Internet, we can achieve the so-called One One Marketing and One One business, and then E business. Therefore, e-commerce will become another direction for the development of database technology in the future.

Database technology for specialized application fields: Many researchers have researched database technology from a practical perspective and proposed database technologies suitable for the application field, such as engineering databases, statistical databases, scientific databases, spatial databases, geodatabases, etc. Such databases have not changed much in principle, but they have been combined with certain applications, thereby strengthening the system's ability to support related applications, especially in terms of data models, languages, and queries. Some researchers believe that with the deepening of research work and the application of database technology in practical work, database technology will develop more towards specialized application areas.

Database technology basic concepts

Data and data processing

Data (Data) is used to describe various concrete things or abstract concepts in the real world. It can store symbols with clear meanings, including numbers, words, graphics and sounds. Data processing refers to the processing of various forms of data The sum of a series of activities of collection, storage, processing and dissemination. One of its purposes is to extract from a large amount of raw data, and to derive valuable information for people as the basis for action and decision-making; the second purpose is to Use computer technology to scientifically save and manage complex, large amounts of data so that people can easily and fully utilize these valuable information resources.

database

A database (DataBase, DB) is an organized, shareable collection of related data stored in computer-assisted storage. The database has the following characteristics.

Database is a collection of data with logical relationships and deterministic meaning.

Databases are designed, built, and loaded for clear application goals. Each database has a set of users and serves the application needs of these users.

(3) A database reflects certain aspects of objective things, and needs to always be consistent with the state of objective things.

Database management system and its basic functions

Database management system (DataBase Management System, DBMS) is the system software for managing the database. Its function is to effectively organize and store data, obtain and manage data, accept and complete various data access requests made by users. Can support relationships Database management system based on data model is called Relational DataBase Management System (RDBMS).

The basic functions of RDBMS include the following 4 aspects:

Data definition function: RDBMS provides a data definition language (Data Definition Language, DDL), the use of DDL can easily define the relevant content in the database. For example, the definition, creation and modification of the database, tables, fields and indexes.

Data manipulation function: RDBMS provides a data manipulation language (Data Manipulation Language, DML), which can be used to implement basic operations such as inserting, modifying and deleting data in the database.

(3) Data query function: RDBMS provides a Data Query Language (DQL), and DQL can be used to implement data query operations on the database.

Data control function: RDBMS provides a Data Control Language (DCL). DCL can be used to complete database operation control functions, including concurrency control (that is, to deal with problems that may occur when multiple users use some data at the same time). Checking and execution of integrity constraints, internal maintenance of the database (such as automatic maintenance of indexes), etc. Many of the above functions of the RDBMS can be implemented through Structured Query Language (SQL). SQL is A standard language in a relational database. The basic syntax in SQL is the same in different RDBMS products. In addition, DDL, DML, DQL, and DCL are also SQL.

3.4 Database application system and its composition

A database application system is also referred to as a database system for short. It refers to a computer system with database technology support. It can implement the functions of organizing and dynamically storing a large amount of related data and providing data processing and information resource sharing services.

Various types of personnel are mainly involved in the requirements analysis, design, development, use, management and maintenance of database application systems. They play different roles and play different roles in the development, operation and maintenance of database application systems. The personnel mainly include the following.

End users.

System Analyst.

(3) Application programmer.

Database Administrator (DBA).

Application of database technology

From its application mode, database technology mainly plays two roles.

The role of information system development. Using database technology and Internet technology, combined with specific programming languages, you can develop an information system to solve the problem of business data input and management. In the development of information systems, the basic functions of RDBMS are mainly used , Namely data definition function, data manipulation function, data query function and data control function.

Data analysis and display function. Use the data query function of RDBMS to perform association and combination analysis on the data in the database, and display the analysis results in the form of tables, graphs or reports to solve the problem of comprehensive utilization of business data.