Which one is best in performance SQL SERVER 2008 or MYSQL

for most of my project SQL Server 2008 provide the best performance for big data

SQL Server 2008 will provide best performance compare to MY SQL.

There is very little difference in performance in the two of them. MySQL performs better on the Unix/Linux-platform and improves when 64bit-OS is used. Thanks to the database-structure, the isn't that much CPU needed for accessing the database. However, most comparisons date from MS-SQL 2000 or MS-SQL 2005.

According to a reasonable test with MS-SQL 2008 with 64bit, Microsoft performs better, even when MySQL has been running on Unix 64bit and tuned for performance.

Depending on the calls you might create, MySQL locks the entire table as opposed to the row-locking of MS-SQL. A large number of concurrent calls might lock the system, but that is a technical consideration and not an answer to your question.

So, in conclusion:

If you are able to install MS-SQL on  64bit OS and have a disk dedicated for data-storage, it will perform better than MySQL. If you are running a 32bit OS, MySQL will do better. Assuming the OS will not be the problem, my vote goes to MS-SQL 2008.

According to me Microsoft SQL Server 2008 outperforms MySQL as a database platform in all business-critical areas, where it provides a large resource network, industry leading performance and enterprise ready scalability, the highest level of security, the highest availability, a comprehensive Business Intelligence (BI) and platform all at a low total cost of ownership (TCO).  So with so many factors it makes SQL server way better than MySQL