The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 10: Integrating FILESTREAM with other SQL Server FeaturesIn most cases, it will be tedious to selectively exclude the FILESTREAM columns whilequerying a database snapshot. It would have been much easier if SQL Server simplyreturned NULL for the FILESTREAM columns instead of raising an error, but it is possiblethat this was not done because one of the main features of the FILESTREAM storage isthe transactional consistency between the relational data and FILESTREAM data.FILESTREAM and Change Data CaptureChange Data Capture (CDC) was introduced with SQL Server 2008. When this featureis enabled, SQL Server keeps track of the modifications (inserts, updates, and deletions)on the tables being tracked. The data capture takes place asynchronously (by reading thetransaction log), which eliminates the additional overhead you may have with a triggerbasedcustom data capture framework. CDC can be configured to capture data modificationsat the table level as well as at the column level.More on CDCFor a more detailed discussion of CDC, see the Microsoft article, Tuning the Performance of Change DataCapture in SQL Server 2008 at: http://brurl.com/fs25.Books Online states that CDC does not support any of the new data types introduced inSQL Server 2008. If you decide to enable CDC on your FILESTREAM-enabled tables, youmust exclude the FILESTREAM columns from the capture list.So what happens if you enable CDC on a table that contains FILESTREAM columns?CDC will capture those columns as VARBINARY(MAX) columns.377