Is it possible to access the FILESTREAM share?

What I mean is being able to access it through Windows Explorer 开发者_JS百科or other programs. I believe the answer is that it isn't possible. But I really want to know why it's not allowed. It seems that the files could be made available read-only through the network share.

You can't access the Filestream share directly and explore around. Any open to a Filestream file needs to be done using the path retrieved from SQL Server and by using NtCreateFile (or a wrapper) with the appropriate transaction context passed in through the EABuffer.

It is possible to create a new share and point it to the physical location of the files, however this is pretty pointless as there's no supported way to resolve a SQL Filestream row to a physical file location (the RsFx filter driver handles these conversions internally), the file location may change at any time due to concurrent updates / partition changes, and you'll need to relax security on the folder to an unacceptable level. It can also cause corruptions in the database if you move or delete files without the knowledge of SQL Server. Any locks held on physical files will interfere with deletes as mentioned in dportas' comment.

I agree it would be great to be able to browse a namespace of the Filestream files through explorer and open files directly through applications without requiring an application rewrite.

Yes it is possible. The point of filestream however is that you get that access via the filestream API rather than direct through the filesystem. Bear in mind that the file name could change without warning - for example updates may cause a new filestream file to be created. Possibly if you are holding file system locks (even shared locks) on a file that is needed by SQL Server then that may cause a contention problem. So if you access the data direct through the file system the results will be unsupported and may be unreliable - but then again it might work :-)

Yes it is possible if you are also using FileTables (I am using Sql Express 2017). When in Sql Server Configuration Manager, right click on your server instance, select Properties, and then go to the FILESTREAM tab. Check the "Allow remote clients access to FILESTREAM data". You may have to stop/start your instance. Now you can browse to the share, which is named according to your instance (in my case SqlExpress). In my database (SimioPortal) I had created a file (BlobStore) where I stored my files. So, at the command prompt I can now type: dir \localhost\sqlexpress\SimioPortal\blobstore and see a list of my files. You can do a similar thing in File Explorer.