The purpose of this book is to make aware about what probable causes are & how to troubleshoot when we face any kind of SQL Server database performance issues. Performance tuning means to optimize the performance of SQL Server/ database/ instance by adjusting/ identifying the various bottlenecks causing degradation in database. If SQL Server instance/ database is not properly tuned or optimized, obviously we will face issues like slowness, bad performance of database which relatively affect performance of related application as well. So it's quite mandatory to have your database or SQL Server instance properly tuned to perform optimally. Whenever there is any database/ SQL Server performance issues, there might be various parameters/ factors included which might cause database/ SQL Server performance degradation.