Aug

DBTalk – Group By vs Select Distinct

Here’s something to contemplate:

What’s the difference between “group by” and “select distinct” in a simple query like:

select distinct a.LastName
from   dbo.Account a with (nolock)

could be rewritten as:

select   a.LastName
from     dbo.Account a with (nolock)
group by a.LastName

Who can tell us what the difference in execution would be? When would you pick one over the other?

Posted by Ben Griswold Samples, TSQL Subscribe to RSS feed