The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 11: FileTableThis allows for in-place (or partial) updates to the files, potentially resulting in significantperformance enhancements over other FILESTREAM scenarios. This enhancementcomes at the cost of transactional integrity. When a file is deleted using non-transactionalaccess, the FILESTREAM file will remain and follow the same rules for garbage collectionas other garbage files.FileTable namespaceThe namespace of a FileTable refers to its file and folder structure. In order to navigateto a FileTable's root folder, you need to know the machine name, the instance-levelFILESTREAM share name, the database-level folder name and the FileTable-level foldername. The root path can then be constructed like this:\\servername\instance-share\database-directory\FileTable-directorySQL Server 2012 provides several functions to obtain the correct names of the share andfolders. Assuming a default SQL Server instance with default FILESTREAM share name,a database called NorthPole with default FILESTREAM directory name, and a FileTablecalled Documents with a default FileTable directory name, the UNC path would be:\\servername\MSSQLSERVER\NorthPole\DocumentsIn order to implement an NTFS-compatible structure in SQL Server tables (referred toas "FileTable semantics" in Books Online), FileTable uses many constraints, computedcolumns and defaults.Constraints and computed columns can cause a lot of overhead if many operationsare performed on a FileTable in short order. You might be performing more operationsthan usual if the namespace of the FileTable is being reorganized, such as when you aremoving files from one folder to another. Another example might be a bulk load operation.On those occasions, you may consider disabling the constraints to achieve better398