Question

What is the cost, percentage-wise, in query plan execution?

SELECT a.au_fname + ''+ a.au_lname AS 'Author Name',
t.title
FROM authors a INNER JOIN titleauthor ta
ON (a.au_id = ta.au_id) INNER JOIN titles t
ON (ta.title_id = t.title_id)

select * from authors

Answer 1

In SQL Server:

Cost percentage is the relative percentage to the whole batch of queries executing. If you are executing a single query, the percentage for that would be always 100%.

Each query in the batch that is
analyzed is displayed, including the
cost of each query as a percentage of
the total cost of the batch.

http://msdn.microsoft.com/en-us/library/ms178071.aspx