Fastest way to determine if record exists

Question

As the title suggests... I\'m trying to figure out the fastest way with the least overhead to determine if a record exists in a table or not.

Sample query:

Answer 1

Nothing can beat -

SELECT TOP 1 1 FROM products WHERE id = 'some value';

You don't need to count to know if there is a data in table. And don't use alias when not necessary.