Use the FILESTREAM tag when referencing Microsoft's SQL Server FILESTREAM feature which allows developers/admins to store binary data on the file system instead of in the tables.


Much data is unstructured, such as text documents, images, and videos. This unstructured data is often stored outside the database, separate from its structured data. This separation can cause data management complexities. Or, if the data is associated with structured storage, the file streaming capabilities and performance can be limited.

FILESTREAM integrates the SQL Server Database Engine with an NTFS file system by storing varbinary(max) binary large object (BLOB) data as files on the file system. Transact-SQL statements can insert, update, query, search, and back up FILESTREAM data. Win32 file system interfaces provide streaming access to the data.

FILESTREAM uses the NT system cache for caching file data. This helps reduce any effect that FILESTREAM data might have on Database Engine performance. The SQL Server buffer pool is not used; therefore, this memory is available for query processing.

When to use FILESTREAM

  • Objects that are being stored are, on average, larger than 1 MB.
  • Fast read access is important.
  • You are developing applications that use a middle tier for application logic.

Advantage of FILESTREAM Storage

FILESTREAM storage is implemented as a varbinary(max) column in which the data is stored as BLOBs in the file system. The sizes of the BLOBs are limited only by the volume size of the file system. The standard varbinary(max) limitation of 2-GB file sizes does not apply to BLOBs that are stored in the file system.