SQL Server FileStream feature provides an efficient way of storing and managing large binary objects (BLOBs) in a SQL Server Database. FileStream enables the data to be stored on the file system rather than being directly saved in the database, which makes it ideal for handling large BLOBs that can consume a lot of database storage and memory resources.
When the FileStream feature is enabled on a SQL Server, it creates a special type of file group called FileStream File Group. This file group is used to store the BLOB data as a collection of files outside the database. These files are then accessed through a special type of SQL Server column called the FileStream column.
To illustrate the use of SQL Server FileStream, let’s consider an example of storing images in a database. Traditionally, storing images in a database would involve creating a SQL Server column of type VARBINARY(MAX) to hold the image data. This approach soon becomes impractical when dealing with a large number of images because it consumes a lot of memory and storage resources. In contrast, using the FileStream feature makes it easy to manage large images in the database.
To use FileStream, you need to configure the SQL Server instance to support FileStream, create a FileStream file group, and add a FileStream column to the table where you want to store the data. The following T-SQL script shows how to create a table with a FileStream column:
CREATE TABLE Images
(
ImageID int PRIMARY KEY,
ImageDescription varchar(50),
ImageData varbinary(max) FILESTREAM
)Notice how we use “FILESTREAM” as the data type for the ImageData column. This tells SQL Server to store the large binary data outside the database file on the file system. The FileStream data can then be accessed using the special FileStream API in Transact-SQL or through .NET programming.
By using the FileStream feature to store BLOBs, we can take advantage of the file system features for managing large files, such as backup and recovery, file compression, and remote storage. FileStream also provides better performance for inserting, updating, and retrieving large binary data compared to traditional methods of storing BLOB data in SQL Server columns.
In conclusion, the FileStream feature in SQL Server provides a robust and efficient way of storing and managing large binary objects in a database. By using FileStream, you can take advantage of file system features for managing large files and achieve better database performance when working with BLOB data.