What are the characteristics of the database?

A database is a warehouse for storing data. Its storage space is very large, and it can store millions, tens of millions and hundreds of millions of pieces of data. But the database does not store data at will, and there are certain rules, otherwise the query efficiency will be very low. Today's world is an internet world full of data, full of a lot of data. That is, this internet world is the data world. There are many sources of data, such as travel records, consumption records, web pages visited, messages sent and so on. Besides text data, images, music and sounds are all data.

Database is a computer software system that stores and manages data according to data structure. The concept of database actually includes two meanings:

(1) Database is an entity and a "warehouse" that can reasonably store data. Users store the transaction data to be managed in this "warehouse", and the concepts of "data" and "library" are combined to form a database.

(2) Database is a new data management method and technology, which can organize data more appropriately, maintain data more conveniently, control data more strictly and use data more effectively.

Development situation

In the history of database development, database has experienced various stages of development, such as hierarchical database, network database and relational database, and database technology has developed rapidly in all aspects. Especially relational database has become the most important database product at present. Since 1980s, almost all the new database products of database manufacturers have supported relational databases, and even some non-relational database products have almost interfaces supporting relational databases. This is mainly because the traditional relational database can better solve the problem of managing and storing relational data. With the development of cloud computing and the arrival of the era of big data, relational databases are increasingly unable to meet the demand. This is mainly because more and more semi-relational and non-relational data need to be stored and managed by databases. At the same time, the emergence of new technologies such as distributed technology also puts forward new requirements for database technology, so more and more non-relational databases begin to appear. This kind of database is very different from the traditional relational database in design and data structure. They emphasize the high concurrent reading and writing of database data and the storage of big data. This kind of database is generally called NoSQL (not just SQL) database. However, the traditional relational database still maintains strong vitality in some traditional fields.

Database management system is a computer software system designed for database management, which generally has basic functions such as storage, interception, security and backup. Database management systems can be classified according to the database models they support, such as relational and XML. . Or classified according to supported computer types, such as server clusters and mobile phones; Or classified according to the query language used, such as SQL and XQuery；; Or according to the focus of performance impulse, such as maximum scale and maximum running speed; Or other classification methods. No matter which classification method is used, some DBMS can cross categories, such as supporting multiple query languages at the same time.

The database management system is the core component of the database system, which mainly completes the manipulation and management functions of the database, realizes the creation of database objects, the query, addition, modification and deletion of data stored in the database, and the user management and authority management of the database. Its security is directly related to the security of the whole database system, and its protection measures mainly include:

(1) Use genuine database management system and install relevant patches in time.

(2) Do a good job in user account management, disable the default super administrator account or set a complex password for the super administrator account; Assign a special account to the application to be accessed; Set user login time and login failure times to prevent violent password cracking.

(3) When allocating user access rights, adhere to the principle of minimum access rights allocation, and restrict users to only access specific databases, and cannot access other databases at the same time.

(4) Modify the default access port of the database, use a firewall to shield other ports open to the outside world, and prohibit all external ports from detecting.

(5) Encrypt and store important data and sensitive data stored in the database to prevent data leakage caused by database backup or data file theft.

(6) Set the backup strategy of the database to ensure that the database can be quickly recovered after being destroyed.

(7) Manage the system stored procedures in the database reasonably, disable unnecessary stored procedures, and prevent database detection and attack by using stored procedures.

(8) Enable the database audit function, and conduct comprehensive event tracking and logging on the database.