The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 2: Getting Started with FILESTREAMTo further understand the FILESTREAM filegroup, let's take a look at the minimal T-SQLscript that creates a FILESTREAM-enabled database (Listing 2-1)./*01*/ CREATE DATABASE NorthPole ON/*02*/ PRIMARY (/*03*/ NAME = NorthPole,/*04*/ FILENAME = 'C:\ArtOfFS\Demos\Chapter2\NorthPole.mdf'/*05*/ ), FILEGROUP NorthPole_fs CONTAINS FILESTREAM(/*06*/ NAME = NorthPole_fs,/*07*/ FILENAME = 'C:\ArtOfFS\Demos\Chapter2\NorthPole_fs')/*08*/ LOG ON (/*09*/ NAME = NorthPole_log,/*10*/ FILENAME = 'C:\ArtOfFS\Demos\Chapter2\NorthPole_log.ldf')Listing 2-1:Sample T-SQL script to create a FILESTREAM-enabled database.Lines 05, 06, and 07 specify the configuration parameters for the FILESTREAM filegroup.A closer look will highlight a few differences between a FILESTREAM filegroup definitionand the definition of a data or log filegroup.First of all, the FILESTREAM filegroup uses the additional clause CONTAINSFILESTREAM which tells SQL Server to treat the filegroup as a FILESTREAM filegroup.This is important, because SQL Server needs to do some additional work to configure theFILESTREAM filegroup.Next, notice the value of the FILENAME parameter in line 07; while the FILENAMEparameters of data files and log files point to a disk file, for a FILESTREAM filegroup itpoints to a folder. The FILESTREAM data will be stored in multiple files, with one file foreach data value. Therefore, it makes sense that the FILESTREAM filegroup points to afolder, rather than a single file.When you create a FILESTREAM-enabled database, SQL Server will create and configurethe folder specified as the FILESTREAM data container. It is very important to ensurethat the leaf-level folder within the path that you provide does not already exist, so thatSQL Server can go ahead and create it. Please also note that SQL Server will create only51