The Art of SQL Server FILESTREAM - Red Gate Software

Chapter 12: Planning, Configuration and Best PracticesVARBINARY(MAX) column. To help you make this decision, do some performance teststo compare FILESTREAM and VARBINARY(MAX) storage options based on your specificworkload and usage pattern.Keep an additional column to store the type of fileor extensionIn many cases, a FILESTREAM column is expected to store more than one type of file. Forexample, a product catalog application might store multiple types of files (.jpg, .png,etc.) in the image column, and a document management application might store multipletypes of documents (Word, Excel, etc.), and so on.An additional column that specifies the file type can be beneficial. For example, inChapter 10 we saw that full-text indexing expects an additional column in the tablethat stores the file extension. Based on the file type, the index component identifies theIFilter for the file and indexes the content. Even if you do not use full-text indexing, itmay be helpful to keep a file type column, for example to identify the content type to theclient application.Identifying the type of file from a file headerMost file types have a header section that stores various pieces of information about thecontent of the file. For example, most image file types keep a file header that specifies thetype of file, dimension of the image, and so on.While it is recommended that you keep an additional column that specifies the file type,in the real world you may end up in a situation where there is no such column. Forexample, assume that the application stores different types of images in the FILESTREAMcolumn of a product catalog table. In the absence of an extra column which stores452