Question 2: What are the commonly used databases? What's the difference between them and the open source Mysql top? PostgreSQL is open source.
Commercial Oracle/SQL Server/DB2 is charged.
Question 3: What are the three commonly used databases? At present, the relational database of database management system is the leading product of commercialization, and its technology is relatively mature. Although the advanced technology of object-oriented database management system makes the database easy to develop and maintain, it is not a mature product. Leading relational database management systems at home and abroad, Oracle Bone Inscriptions, Sybase, Informix and INGRES. These products support multiple platforms, such as UNIX, VMS and Windows, but with different levels of support. And mature IBM DB2 relational database. However, DB2 is an AS/400 series embedded in IBM and only supports OS/400 operating system.
? 1. Relational database
? MySQL is the most popular open source SQL database management system at present, which is published and supported by MySQL AB Company. MySQL AB is a commercial company based on MySQL. Is it a successful business model combining open source value? And methodology of the second generation open source companies. MySQL is a registered trademark of MySQL AB.
? MySQL is a fast, multi-threaded, multi-user and robust SQL database server. MySQL server supports the use of critical tasks and heavy production systems, and it can be embedded into a large-scale configuration (large-scale deployment) software.
? Compared with other database management systems, MySQL has the following advantages:
? (1)MySQL is a relational database management system.
? (2)MySQL is open source.
? (3)MySQL server is a fast, reliable and easy-to-use database server.
? Client/server or embedded system in MySQL server.
? (5) You can use MySQL software.
2. It's from 2. SQL Server？
? SQL Server is a database management system developed by Microsoft and the most popular database at present, which is used to store data on the network. It has been widely used in e-commerce, banking, insurance, electric power and other database-related industries.
? The latest version of SQL Server 2005, which can only run stably under the Windows operating system, is a very important database. Parallel implementation and * * * storage mode are immature, so it is difficult to cope with more and more users, and the data volume is limited and extensible.
? SQL Server provides network and e-commerce functions, such as rich XML and Internet standard support, extensive data can be accessed conveniently and safely through the Web, and powerful and flexible network-based security and application management. In addition, because of its ease of use and friendly user interface, it has been well received by users.
? 3. Oracle
? The company's first database is usually Oracle Bone Inscriptions. Founded in 1977, the company was originally a company specializing in developing databases. Oracle Bone Inscriptions has always been a leader in the field of database. 1984, the first relational database was transferred to a desktop computer. Then, Oracle5 introduced the new concepts of distributed database and client/server architecture for the first time. The first row locking mode of Oracle Bone Inscriptions Company and the support of symmetric multiprocessing computer ... The latest Oracle object technology has become a relational object database system. At present, Oracle Bone Inscriptions's products cover dozens of models of large, medium and small computers, and Oracle database has become the most widely used relational data in the world.
Oracle database products have the following excellent features.
? (1) compatibility
? Oracle products use standard SQL and have passed the test of NIST National Bureau of Standards and Technology. Compatible with IBM's SQL/DS, DB2 and Angel's IDMS/R.
? (2) portability
Oracle Bone Inscriptions's products can run on various hardware and operating system platforms. It can be installed on more than 70 different VMS systems, such as DOS, UNIX, Windows and other operating systems and minicomputers.
? (3) Lenovo
Oracle Bone Inscriptions is connected with various communication networks and supports various protocols (TCP/IP protocol, DECnet, LU6.2 work, etc.). ).？
? (4) High productivity
? Oracle provides a variety of development ... >>
Question 4: What kinds of databases are commonly used now? MSSQL and MySQL, two kinds of sqlserver, often called MSSQL, are products of Microsoft, but MySQL is not. MySQL is an open source product of a company called MySQL AB, which is free and can be used across platforms. MSSQL is very expensive and is generally only used under Windows.
Question 5: What FOXBASE are commonly used in large databases?
relational database
Neither of them is a large database management system.
PB is an ide for database application development, not a database management system at all.
Foxbase is a product of dos era, and it was renamed foxpro in windows era, which belongs to a small database system at the desktop stand-alone level. Mysql is a lightweight, but open source, widely used in small websites. The real heavyweight products are Oracle and DB2, which are mostly used in key industries such as banks. Microsoft's MS SQLServer is smaller than DB2 and Oracle, and more common in small and medium-sized enterprises. Sybase can be said to be dying.
Question 6: What are the common database file formats? Dbf dbase file, the format created by ashton-tate, act can be used! , lipper, foxpro, arago, wordtech, xbase and other similar databases or products related to databases can be identified. Available data file (which can be opened by excel 97), oracle 8. 1.x tablespace file; Dba is an access file; Nsf lotus notes database; Mdf and ldf are sql server files; 2. In addition, you still have a lot of database files defined by software developers themselves, mostly using dat, or converting dba into dat, and processing them through program file name conversion. 3.odb++ is an extensible ascii format, which can save all engineering data needed for pcb manufacturing and assembly in a single database. It is a bridge that can connect databases with various data formats. This is a two-way format that allows uploading and downloading data.
Question 7: What are the common database application systems? Nowadays, many enterprise-level softwares are based on databases.
For example:
ERP: enterprise resource management plan
CRM: customer relationship management
office automation
Ministry of Railways 12306 Online Booking System.
. . .
Question 8: What are the commonly used database software? 1)MYSQL:
MySQL is developed, published and supported by MySQL AB. It is a fast, multi-threaded, multi-user and robust SQL database server and the most popular open source SQL database management system at present. relational database
AB is a commercial company based on MySQL developers. It is a second-generation open source company, which uses a successful business model to combine open source value with methodology. MySQL is MySQL.
Registered trademark of AB. MySQLMySQL server supports the use of mission-critical and heavy production systems, and can also be embedded in large-scale configurations (large-scale-
Deploy) software.
2) Visit:
ACCESS is a relational database that comes with the system, and there is no need to set up space storage separately. Relational database is composed of a series of tables, and tables are composed of a series of rows and columns. Each row is a record, each column is a field, and each field has a field name. Field names cannot be duplicated in the table. The Access database is saved as a file with the file extension MDB. Access database, as a common database for developing websites, is generally used together with ASP programs. When the database is too large, it can be converted into MSSQL database, and the two can be converted to each other.
3)MSSQL:
SQL Server, also produced by Microsoft, is a database platform that provides a complete solution from server to terminal. The database server part is a database management system for establishing, using and maintaining databases.
MSSQL features: large data carrying capacity, fast data storage speed and strong stability, which is suitable for small and medium-sized enterprises to develop databases commonly used in websites and office systems.
4) Oracle Bone Inscriptions:
Oracle Corporation is the largest information management software and service provider in the world, established in 1977 and headquartered in redwood, California, USA.
Coastal. Oracle software can run on PC, workstation, minicomputer, mainframe, massively parallel computer, PDA and other computing devices. With more and more enterprises turning to e-commerce, Oracle's solutions with strong e-commerce capabilities provide enterprises with efficient means to expand the market, improve work efficiency and attract more customers. The complete e-commerce products and services provided by Oracle include: for establishing and delivering Web-based Internet platforms;
Comprehensive and comprehensive commercial application with Internet capability; Strong professional services to help users implement e-commerce strategies, design, customize and implement various e-commerce solutions.
Question 9: What are the common database management systems? What are their characteristics? 1.IBM's IBM is a pioneer and leader in the field of relational databases. IBM completed the prototype of System R in 1977, and began to provide integrated database server-System/38 in 1980, followed by SQL/DSforVSE and VM. Its initial version is closely related to the research prototype of system R, and DB2 forMVSV 1 was launched in 1983. The goal of this version is to provide the simplicity, data independence and user productivity promised by this new scheme. DB2 for MVS provides powerful online transaction processing (OLTP) support in 1988, and implements distributed database support in 1989 and 1993 respectively. The recently launched DB2 Universal Database 6. 1 is a model of Universal Database, the first multimedia relational database management system with online function, and supports a series of platforms including Linux. 2. Oracle Bone Inscriptions Oracle Bone Inscriptions, formerly known as SDL, was founded by Larry Ellision and two other programmers in 1977. They developed their own fist products and sold them in the market. 1979, Oracle launched the first commercial SQL relational database management system. Oracle Company is one of the earliest manufacturers to develop relational databases, and its products support the most extensive operating system platforms. At present, the market share of Oracle relational database products is among the best. 3.Informix Informix was founded in 1980 to provide professional relational database products for Unix and other open operating systems. The company name Informix is taken from the combination of Information and Unix. Informix's first relational database product that really supported SQL language was Informix SE(StandardEngine). InformixSE was the main database product under the microcomputer Unix environment at that time. It is also the first commercial database product transplanted to Linux. 4.Sybase Sybase was founded in 1984. The company name "Sybase" comes from the combination of "system" and "database". Bob Epstein, one of the founders of Sybase Company, is the main designer of Ingres University Edition (a relational database model product at the same time as System/R). The first relational database product of this company is Sybase SQLServer 1.0, which was launched in May 1987. Sybase first put forward the idea of client/server database architecture, and took the lead in implementing it in Sybase SQLServer. 5.SQL Server 1987, Microsoft and IBM jointly developed OS/2, and IBM bundled OS/2Database Manager in its OS/2 ExtendedEdition system, but Microsoft's product line still lacks database products. Therefore, Microsoft turned its attention to Sybase and signed a cooperation agreement with Sybase to develop a relational database based on OS/2 platform by using Sybase technology. 1989, Microsoft released the 1.0 version of SQL Server. 6.PostgreSQL PostgreSQL is a relational database management system (ORDBMS), which is the object of free software and has complete characteristics. Many of its features are the predecessors of many commercial databases today. PostgreSQL originally started with the Ingres project of BSD. The features of PostgreSQL cover SQL-2/SQL-92 and SQL-3. First of all, it contains the support of the richest data types in the world. Secondly, PostgreSQL is the only free software database management system that supports transaction, sub-query, multi-version parallel control system and data integrity check. & gt
Question 10: What are the common database security technologies? What database security means to protect the database and prevent data leakage, tampering or destruction caused by illegal use?
Security problem is not unique to database system, all computer systems have this problem. It is only stored in a large amount of data in the database system and directly enjoyed by many end users, thus making the security problem more prominent. Whether the system security protection measures are effective is one of the main indexes of the database system. The security of database and computer system, including the security of operating system and network system, are closely related and mutually supportive.
Common methods and technologies to realize database security control are:
(1) User identification and authentication: The system provides a way for users to identify their own names or identities. Every time a user requests to enter the system, the system will check and provide the right to use the system after passing the authentication.
(2) Access control: Through the definition of user rights and the check of legal rights, it is ensured that only users with legal rights can access the database, and all unauthorized personnel cannot access the data. For example, C2-level discretionary access control (I)AC, Bl-level mandatory access control (M.AC).
(3) View mechanism: define views for different users, and hide the data that needs to be kept secret from users without permission through the view mechanism, thus automatically providing a certain degree of security protection for the data.
(4) Audit: establish an audit log, automatically record all the user's operations on the database and put them into the audit log. DBA can use the information of audit trail to reproduce a series of events leading to the current situation of the database, and find out who, when and what illegally accessed the data.
(5) Data encryption: Encrypt the stored and transmitted data, so that people who don't know the decryption algorithm can't know the content of the data.