In a previous article Online non-NULL with values column add in SQL Server 2012 I talked about how adding a non-null column with default values is now an online operation in SQL Server 2012 and I mentioned how the situation when the newly added column may increase the rowsize can result in the operation being performed offline:

In the case when the newly added column increases the maximum possible row size over the 8060 bytes limit the column cannot be added online.

In this article I want to show you how such a situation can arise and how it impacts even the case that prior to SQL Server 2012 was always online, namely adding a nullable column. Lets consider the following example:

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