Performance tunning is a must for any database because without your Database is the same as retrieving data from file system.
Many times in your organization an issue is raised that SQL server database is very much slow and its performance is not up to the mark. First thing that comes in mind is are indexes correctly applied to table that are being used? And most of the time indexes are applied, than what is the issue.
Most users think that only indexes are the reason for bad performance of a SQL server database, this is not true, there are many other reasons for slow response from your DB.
Following are some of the areas each of which are to be checked separately for resolution of performance issues in a SQL Server database:
Optimization of Queries used
Maintaining up to date Statistics
Logical Query Processing
Hardware Issues (slow hard disks, CPU, Memory etc)
If all above areas are checked and planned properly, then probability of slow response from a SQL server database are very much minimized.