The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 1: Storing and Managing Unstructured Dataversioning to make sure the right file system data is restored with the right databasebackup. It is also important to make sure to keep the same file system structure inthe new location so that the disk files maintain the same path as that stored in therelational tables.When the LOB data is stored outside the database, the relational data can be restored toa given point in time, but not the file system changes, since the file system on its owndoes not track modifications and does not allow you to roll back the changes, once thefile is saved.SecurityWhen LOB data is stored within the database, the security can be managed at the SQLServer level. This reduces the administrative complexity and aligns LOB security with thesame security processes applied to the associated relational data.If LOB data is stored outside the database, separate measures must be put in place tosecure the file system. The relational data and LOB data are disconnected (or connectedwith just a weak link which stores the path to the file in a relational column), andmanaging user access permissions is a major challenge.PerformanceYou're probably thinking that, on almost all levels, storing LOB data in the database ispreferable to storing it in the file system. However, despite the numerous advantagesdiscussed so far, of storing LOB data in the database, performance is the one considerationthat makes it a non-feasible option for most applications.The relational database engine is optimized to process relational data; storing andprocessing huge chunks of LOB data is not always done with the same ease.35