Comparison of four major databases (SQL Server, Oracle, Sybase, and DB2)

Openness:

SQL Server
It can only run on windows without any openness. The stability of the operating system is very important to the database. The Windows9x series products focus on desktop applications, and the NT Server is only suitable for small and medium enterprises. And windows
The reliability, security, and scalability of the platform are very limited. It is not as tested as UNIX, especially when processing big data
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.
Sybase ASE
Can run on all major platforms (including windows ). However, due to the low integration level between Sybase and OS, versions earlier than version 11.9.2 require many OS and DB-level patches. In a multi-platform hybrid environment, some problems may occur.
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:
SQL Server
The parallel implementation and coexistence model are not mature. It is difficult to process the increasing number of users and data volumes. Limited scalability.
Oracle
The parallel server enables a group of nodes to share the work of the same cluster to expand the capabilities of the windoupstream, providing high-availability and high-scalability cluster solutions. If WindowsNT cannot meet your needs, you can move the database to Unix.
The Parallel Server of Oracle has a high degree of integration with the cluster mechanism of Various UNIX platforms.
Sybase ASE
Although dB switches are available to support its parallel servers, DB switches are not yet mature at the technical level and only support ASE servers with Versions later than 12.5. Because DB switch technology requires a server to act as a switch, thus in the hardware.
DB2
Good concurrency. DB2 expands database management to a parallel, multi-node environment. Database partitioning is a part of a database that contains its own data, indexes, configuration files, and transaction logs. Database partitions are sometimes called nodes.
Security
SQL Server
No security certificate is obtained.
Oracle Server
Obtain the highest level of ISO certification.
Sybase ASE
Obtain the highest level of ISO certification.
DB2
Obtain the highest level of ISO certification.
Performance
SQL Server
Poor performance when multiple users
Oracle
Highest performance, keeping world records of TPC-D and TPC-C under open platform.
Sybase ASE
The performance is close to that of SQL Server. However, the concurrency on UNIX platforms must be better than SQL Server.
DB2
High performance is suitable for data warehouses and online transaction processing.
Client Support and Application Mode
SQL Server
The C/S structure only supports Windows users. You can use ADO, Dao, oledb, and ODBC to connect.
Oracle
Multi-layer network computing supports multiple industrial standards and can be connected by network customers such as ODBC, JDBC, and OCI.
Sybase ASE
The C/S structure can be connected by network customers such as ODBC, jconnect, and CT-library.
DB2
Cross-platform, multi-layer structure, support for ODBC, JDBC, and other customers
Easy to operate
SQL Server
Simple operation, but only graphic interface.
Oracle
Complex: provides both GUI and command lines, and operates the same in WindowsNT and UNIX.
Sybase ASE
Complex: provides both GUI and command lines. However, the GUI is poor and often cannot be in a timely manner. We recommend that you use the command line.
DB2
The operation is simple. Gui and command line are provided at the same time. The operation is the same in WindowsNT and UNIX.
Usage risks
SQL Server
Completely rewritten Code , Has been tested for a long time, and is constantly delayed. Many features require time to prove. Not very compatible.
Oracle
Long development experience is fully backward compatible. It is widely used. There is no risk at all.
Sybase ASE
Backward compatible, but CT-Library Program Migration is not beneficial.
DB2
It is widely used in giant enterprises and has good downward compatibility. Low risk.
After comparison, we can easily find that DB2 is the best database.