Performance is one of most important factor at the time of the application developement. If your application or website is not responding fast to user queries then it's accepted by the users.
Here are the some tips to make fast retrival of data from sql server.
1) Create Index- Indexes are great way to improve your performance. It uniquely indetifys the each row in table.
2) Avoid Cursor- Cursors are time consuming so avoid cursors as much as you can do more work with queries.
3) Avoid Joins- Joins are also time consuming so avoid it.
4) Create Primary and Foreign keys in tables
5) Be sure your tables must have atleast one column that uniquely indetifys each rows