Various relational database management systems

Oracle

Microsoft SQL server2005

Sybase

Informix

DB2

Ingers

Microsoft Access

Visual FoxPro

MySQL

Oracle

Oracle is one of the earliest commercial relational database management systems. It is also a widely used and powerful database management system. As a general database management system
The entire data management function is also a distributed database system that supports various distributed functions, especially Internet applications. As an application development environment, Oracle provides a set of interfaces
User-friendly and fully functional database development tools. Oracle uses the PL/SQL language to perform various operations, and features such as openness, portability, and scalability. Especially in Oracle
In 8i, it supports object-oriented functions, such as support classes, methods, and attributes, making Oracle a type of object/relational database management system.

It has good compatibility, portability, connectability, high productivity, and openness.

Oracle products mainly include database servers, development tools, and products.

Microsoft SQL Server

Microsoft SQL
Server is a typical relational database management system that can run on many operating systems. It uses the transact-SQL language to perform data operations. Because Microsoft
SQL Server is an open system, and other systems can interact with it in good condition. The latest version of Microsoft SQL Server
2008. It features reliability, scalability, availability, and manageability, providing users with a complete database solution.

Sybase

Supports various database application requirements (data warehouse, online transaction processing, decision support system, and small platform application) within the enterprise. Excellent open structures can work on the slave machine, multi-processing system, and other platforms.
2. sybase database features

(1) it is a database based on the customer/Server Architecture
generally, relational databases are based on Master/Slave models. In the Master/Slave structure, all applications run on one machine. The user only sends commands through the terminal or simply views the running results of the application. In the customer/Server structure, applications are run on multiple machines. One machine is the customer of another system or the server of another machine. These machines are connected through the LAN or WAN.
advantages of the customer/server model: it supports resource sharing and load balancing among multiple devices, allowing the environment to accommodate multiple hosts, make full use of the existing systems of the enterprise
(2) It is a truly open database
because of the customer/Server structure, applications are run on multiple machines. Furthermore, applications running on the client do not have to be Sybase products. For general relational databases, pre-compilation is provided to allow applications written in other languages to access the database. Sybase Database, not only provides a simple pre-compiled
translation, but also exposes the application Program interface DB-LIB, third parties are encouraged to write DB-LIB interfaces. Since open customer DB-LIB allows identical calls to be used on different platforms, it makes it easy to access
ask the DB-LIB application to port from one platform to another.
(3) it is a high-performance database
is Sybase really attractive or its high performance. It is embodied in the following aspects:
programmable database
A Programmable database is created by providing a stored procedure. Stored procedures allow users to write their own database subroutines. These child routines are pre-compiled, so you do not have to compile, optimize, and generate query plans for each call. Therefore, the query speed is much faster.
event-driven triggers
A trigger is a special stored procedure. You can use a trigger to start another stored procedure to ensure database integrity.
multi-clue
another innovation in Sybase database architecture is multi-clue. Generally, databases are managed by the operating system
. When multiple users are connected, the system performance will be greatly reduced. The sybase database does not allow the operating system to manage processes, and manages the connection to the database as part of itself.
In addition, Sybase's database engine uses the operating system to manage some hardware resources, such as ports, memory, and hard disks, bypassing the operating system, improved performance

Microsoft Office

Microsoft
Access is a very popular desktop database management system in windows. Use Microsoft
Access does not require writing anyCodeYou can complete most data management tasks with visual operations. In Microsoft
The Access database includes many basic elements that constitute the database. These elements are the tables that store information, the forms that display the human-computer interaction interface, the query of effective data retrieval, the report of information output carrier, and the improvement
Application Efficiency macros and powerful module tools. It can be connected to other databases through ODBC for data exchange and sharing, as well as data exchange with office software such as Word and Excel
Change and share, and embed and link audio, images, and other multimedia data in the database through object link and embedding technology.

 

DB2 database is a product of IBM, and the core of the DB2 database is also known as the DB2 public server. The dbz database adopts a multi-process, multi-clue architecture and can run on multiple operating systems, adjustments and optimizations were made based on the corresponding platform environment to achieve better performance. It supports various operating platforms from personal computers to Unix servers, from midrange computers to mainframes, from IBM to non-IBM (HP and Sun UNIX systems. DB2 count
The database can run independently on the host in Master/Slave Mode or in the client/server environment. The service platform can be OS/400, Aix, OS/2, HP
For UNIX, Sun Solaris, and other operating systems, the client platform can be OS/2 or windows, DOS, Aix, HP UX, sun
Solaris and other operating systems.

DB2 databases have the following features.

(1) supports object-oriented programming. DB2 supports complex data structures, such as unstructured text objects, which can be searched by Boolean match, closest match, and arbitrary match. You can create user data types and user-defined functions.

(2) supports multimedia applications. DB2 supports large binary objects (BLOB) and allows access to large binary objects and text objects in the database. Binary large objects can be used to store multimedia objects.

(3) supports stored procedures and triggers. You can define complex integrity rules explicitly when creating a table.

(4) supports access to heterogeneous distributed databases and data replication.

In addition, IBM provides many development tools, including visualizer query, visualage, and visualgen. These powerful visual application development tools can greatly improve the efficiency of software development.

Oracle database products are typical representatives of current database technologies. Apart from data
In addition to the database system, there are application systems and development tools. Current Oracle
9 is an object-oriented database system. It is neither a pure object-oriented database nor a pure relational database. It is a combination of the two and is called an "Object Relational Database ". Since Oracle includes several
All database technologies are considered to be one of the enterprise-level master database in the future. Oracle has the following features.

(1) object/link model. Oracle uses the object/link model, which fully supports the traditional
The relational model provides limited support for the object mechanism. Oracle can not only process traditional table structure information, but also manage
And multimedia data types generated by other development tools, such as text, video, graphics, and spatial objects. This approach allows existing software development products to coexist with tool software and Oracle application software, protecting customers
User investment.

(2) Dynamic scalability. Oracle introduces a connection storage pool and multiplexing mechanism to provide
Object support. To support some special data types, you can create software plug-ins. Oracle
8. Advanced network technology is adopted to improve the system's accessibility by improving the sharing pool and Connection Manager. The capacity can be from several GB to several hundred TB, and 0.1 million users can access the system concurrently, in Oracle databases
Tables can accommodate 1000 columns, meeting the needs of current database and data warehouse applications.

(3) Availability and ease of use of the system. Oracle provides flexible and diverse data partitioning functions, one point
A partition can be a large table or a small block with easy index management. It can be partitioned based on data values, effectively improving the system operation capability and data availability, and reducing I/O bottlenecks. Oracle also
Row processing has been improved. Parallel processing has been introduced in operations such as bitmap indexing, query, sorting, connection, and general index scanning, improving the degree of parallelism of a single query.

(4) manageability and data security functions of the system. Oracle provides automatic backup and recovery functions.
Supports large-scale and more refined distributed operating systems, and enhances the concurrency of SQL operation replication. To help customers effectively manage the entire database and application system, Oracle also provides
Management System, the database administrator can manage the Oracle system environment from a centralized console drag-and-drop graphical user interface.

(5) support and openness to multiple platforms. The network structure usually contains multiple platforms, and Oracle can run
On all mainstream platforms, such as Sun solarise, sequent Dynix/PTX, Intel nt, hp ux, Dec UNIX, IBM
Aix. Oracle's heterogeneous services provide the necessary infrastructure for communication with other data sources and services using SQL and PL/SQL.

MySQL is a semi-commercial database that runs on Windows and most Linux platforms. The popularity of MySQL is largely due to its loose nature. The Windows version of MySQL is not free under any circumstances, mySQL is free of charge on any UNIX platform, including Linux.

The mysql client database is a C language database of the customer/Server structure. It means that one customer can query data residing on another machine.
Library. However, the true strength of MySQL lies in the language wrappers in the library. Perl, pathon, and PHP are only part of them. Apache Web servers also have many modules, such as Directory storage.
Various Apache configuration information is allowed for retrieving files. Using MySQL, the application interfaces are simple, consistent, and complete, and the ODBC drivers on multiple platforms are freely available.

MySQL contains some transformations different from the SQL standard. Most of them are designed as a supplement to the deficiency of the SQL script language. However
Is another extension that does make
MySQL is different. For example, link clause search automatically ignores case sensitivity. MySQL also allows users to customize SQL functions, that is, a programmer can write a function and then integrate it.
In MySQL, its performance is no different from any basic function.

MySQL is the middle school in the database field. It lacks most of the main features of a full-featured database, but it is similar
The xbase record storage engine has more features. It requires a service daemon, but does not consume resources as they do. The Query Language allows complex connection queries, but one of the main defects of MySQL is that
There is no standard reference integrity mechanism, and all references must be guaranteed by programmers. Some database administrators may feel that the system lacks the primary database functions, but MySQL has
Value.

Openness :
SQL Server can only be used in Windows
Without any openness, the stability of the operating system is very important to the database. Windows9x series products focus on desktop applications, NT
Server is only suitable for small and medium enterprises. In addition, the reliability, security, and scalability of the Windows platform are very limited. It is not as tested as UNIX, especially the key to processing large data volumes.
Business.
Oracle can run on all major platforms (including windows ). Fully supports all industrial standards. Adopt a fully open policy. Customers can select the most suitable solution. Provide full support to developers.
DB2 can run on all major platforms (including windows ). It is most suitable for massive data volumes. DB2 is the most widely used in enterprise-level applications. Of the 500 largest enterprises in the world, almost 85% of them use DB2 database servers, and about 5% in China to 97 years.

Scalability and concurrency
The SQL Server DB2 parallel implementation and coexistence model is not mature. It is difficult to process the increasing number of users and data volumes. Limited scalability.
The Oracle Parallel server enables a group of nodes to share the work of the same cluster to expand the DRDs function and provide high availability and high scalability solutions for the cluster. If WindowsNT cannot meet your needs, you can move the database to Unix.
DB2 DB2 has good concurrency. DB2 expands database management to a parallel, multi-node environment. Database partitions are a part of the database, including its own data, indexes, configuration files, and transaction logs. Database partitions are sometimes called nodes or database nodes.

Security
SQL Server does not receive any security certificate.
Oracle server receives the highest level of ISO certification.
DB2 has obtained the highest level of ISO certification.

Performance
Poor performance when multiple users of SQL Server
Oracle delivers the highest performance, keeping world records of TPC-D and TPC-C under WindowsNT.
DB2 is suitable for data warehouses and online transaction processing with high performance.

Client Support and Application Mode
SQL Server C/S structure, only supports windows customers, you can use ADO, Dao, oledb, ODBC connection.
Oracle multi-layer network computing, supporting a variety of industrial standards, can be connected by network customers such as ODBC, JDBC, OCI
DB2 cross-platform, multi-layer structure, support for ODBC, JDBC, and other customers

Easy to operate
SQL Server is easy to operate, but only has a graphical interface.
Oracle is complex and provides both GUI and command lines. The operations are the same in WindowsNT and UNIX.
DB2 is easy to operate and provides GUI and command lines at the same time. It operates the same way in WindowsNT and UNIX.

Usage risks
The Code completely rewritten by SQL Server has been tested for a long time and is constantly delayed. Many functions require time to prove. Not very compatible with earlier products. Use requires a certain risk.
Oracle is fully backward compatible with its long development experience. It is widely used. There is no risk at all.
DB2 is widely used in giant enterprises and has good downward compatibility. Low risk.