Fastest way to add a field to a large table I have a fairly large table (approx 400 million rows) and I need to add new column of type bit with NOT NULL constraint. My approach is to add the field without NOT NULL constraint, set the field to 0 and the alter the column to add the NOT NULL constraint.
This is a pretty slow process. Is there a quicker approach?

I am on SQL Server 2014 Enterprise Edition
As you are on Enterprise Edition and version >= 2012 then the information in Online non-NULL with values column add in SQL Server 2012 should apply.

Alter table yourtable 
    add newcolumn bit not null default 0;


Should be metadata only and, unlike your proposed solution, will not have to write anything to all rows.