I've got a column in a table (eg. UserName) which I want to make sure is unique. So I create a unique key for that column and call it IX_Users_UserName.
Now, if I do lots of searching for users based on their username I want to make sure there is an index for that field.
Do I need to create a separate index, or is the unique key also considered an index, just like the primary key is a clustered unique key?
Best Answer
Source
More information from MSDN.
FWIW -- if your constraint doesn't create an index, I would avoid naming it
IX_
as that would typically be assumed to be associated with one (IX = Index).