From recollection, filestream was a feature introduced in SQL Server 2012. I just wonder if it will go the way of some other now abandoned features. Does anybody remember the English Query tool in SQL Server 6.5? What about Notification Services? Will Service Broker go the same way and will filestream go with it?
I have used filestream in a production environment and it served its' purpose. The existing database had a large amount of XML data stored in the database. This was XML about music metadata. Albums, songs and artists. Millions of pieces of XML in the database taking up an enormous amount of space. With the content ingestion of some additional record labels (over 6 million new XML files), we decided to store the XML on a separate file system and have the database access this XML. It was a more effective use of storage as once the XML had been through the initial ingestion it was infrequently required to be accessed. Once it had been proven as a better solution the initial XML was moved to the file stream and accessed via filestream.
Maybe filestream will go the way of other relatively unused features, but it does have its place for storing unstructured data.
The following link is an excellent article on filestream.