The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 11: FileTableNon-transactional accessTransactional access to the BLOB data stored in a FileTable is supported like it is withany FILESTREAM column. The ability to access the files and folders in the FileTable usingtraditional Windows API-based applications requires that access is also allowed outsidethe bounds of a SQL Server transaction. Access to traditional FILESTREAM columns stillrequires a transaction context for reading and writing, even in SQL Server 2012, and thisis regardless of any database-level configuration for non-transactional access.This non-transactional access is configured at the database level, meaning that we canhave multiple databases on the same SQL Server instance with different configurationsfor non-transactional access of FileTables. The options for non-transacted access are:• Off – Non-transactional access to FileTables is not allowed; any access to theFILESTREAM data stored in all FileTables in the database follows the same rules asregular FILESTREAM.• ReadOnly – Non-transactional access to FileTable data is only possible for reading;client applications cannot create or modify files and folders unless they use traditionalFILESTREAM techniques.• Full – Non-transactional access to FileTables is allowed for both reading and writing;client applications can open and save files and create folders using the standardWindows or .NET file I/O APIs.Internally, SQL Server will use the Read Committed transaction isolation level to enforcelocking or concurrency semantics.To configure non-transactional access using SSMS, open the Database Propertieswindow for the database in question, and in the Options page locate the FILESTREAMNon-Transacted Access option and select the appropriate value as shown in Figure 11-1.396