Microsoft® SQL Server 2008 R2 Unleashed

LOB Data Pages

If you want to store large amounts of text or binary data, you can use the text, ntext, and image data types, as well as the varchar(max), nvarchar(max), and varbinary(max) data types. (For information about how to use these data types, see Chapter 24, “Creating and Managing Tables,” and Chapter 38, “Database Design and Performance.”) Each column for a row of these data types can store up to 2GB (minus 2 bytes) of data. By default, the LOB values are not stored as part of the data row, but as a collection of pages on their own. For each LOB column, the data page contains a 16-byte pointer, which points to the location of the initial page of the LOB data. A row with several LOB columns has one pointer for each column.

The pages ...