Application refactoring is one of the most important concept in acquiring the main tasks as a good DBA and is defending SQL Server from bad applications. Huge improvements in this area are possible when all the available resources have been met. And by using DMV queries, extended events and SQL profiles to help in finding the most costly queries and stored procedures. And can check the most frequently executed queries and stored procedures and contains in the middle tier caching and can look for a quite application that cause extra query activity. In the application the stored procedures is being called two or three times when it only need to be called once, just because of mistakes in the applications and developers developed in the code. But as often there is no control over the applications and the coded they have developed. As of this the third party applications and many ISV applications haves serious database usage issues. The Microsoft applications that use SQL Server as a data store are the software notorious for this sort of issues. And all the  famous tasks for having performance issues like Share points, Lync, System center, Team foundation servers.

• Application Refactoring - Is the process of restructuring exiting system code.
• Database - Is a collection of logical related data.

The concepts are very important to work closely with the developers and stakeholders. And all the team will make the best use of the application and even scale better. And in the application level layer all the performance issues will be replicated, and always use the best returns of there investments. And doesn't perform the option in many cases especially with the third party software applications. And just need to use the skills and tools to pinpoint the performance issues from the database servers perspectives. The developer and the management that cause the most pain for the database server that goes beyond the database DBA and then it will reduce the bottlenecks and perhaps move them some place else. And work out of all the problems in all the directions.

• Application Refactoring - Most important concept for acquiring the DBA and other bad applications.