Performance Tuning SQL - How?

Question

How does one performance tune a SQL Query?

• What tricks/tools/concepts can be used to change the performance of a SQL Query?
• How can t

Answer 1

Of course you also need to know the difference between these 3 join

loop join, hash join, merge join

see here: http://msdn.microsoft.com/en-us/library/ms173815.aspx