Thank you the advices.
Indeed, the situation is that i have a system(written in jsp) that is now running on SQL Server 2000 as the backend Database, and i am going to port the system to Linux.
However, the main problem in my case is that the Database(SQL Server) has near 2000 stored-procedures. And I am going to use Database in LInux platform instead of using window sql server.
I knew that there are tools that convert scheme form Sql server to Postgresql, but it seems that i have to rewrite those stored-procedures.
It would be a headache problem.