According to Microsoft,

"If any column that is part of a unique constraint is updated, then SQL
Server implements the update as a 'deferred update'. ... There are also other
situations that might cause a deferred update." --
http://support.microsoft.com/kb/238254

The web page does not describe what those "other situations" might be, and
I've run into one of them. How can I tell if an update is going to be a
deferred update?

Thanks,

--
Aaron Sentell
Sr. Database Administrator
Compass Group USA
Charlotte, NC