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Enable the prerequisites for FileTable

  • Artikel

Applies to: SQL Server

Describes how to enable the prerequisites for creating and using FileTables.

Enabling prerequisites for FileTable

To enable the prerequisites for creating and using FileTables, enable the following items:

Enabling FILESTREAM at the instance level

FileTables extend the capabilities of the FILESTREAM feature of SQL Server. You have to enable FILESTREAM for file I/O access at the Windows level, and on the instance of SQL Server, before you can create and use FileTables.

Enable FILESTREAM at the instance level

For information about how to enable FILESTREAM, see Enable and Configure FILESTREAM.

When you call sp_configure to enable FILESTREAM at the instance level, you have to set the filestream_access_level option to 2. For more information, see FILESTREAM access level (server configuration option).

Allow FILESTREAM through the firewall

For information about how to allow FILESTREAM through the firewall, see Configure a Firewall for FILESTREAM Access.

Provide a FILESTREAM filegroup at the database level

Before you can create FileTables in a database, the database must have a FILESTREAM filegroup. For more information about this prerequisite, see Create a FILESTREAM-Enabled Database.

Enable nontransactional access at the database level

FileTables let Windows applications obtain a Windows file handle to FILESTREAM data without requiring a transaction. To allow this nontransactional access to files stored in SQL Server, you have to specify the desired level of nontransactional access at the database level for each database that will contain FileTables.

Check whether nontransactional access is enabled on databases

Query the catalog view sys.database_filestream_options (Transact-SQL) and check the non_transacted_access and non_transacted_access_desc columns.

SELECT DB_NAME(database_id), non_transacted_access, non_transacted_access_desc
    FROM sys.database_filestream_options;
GO

Enable nontransactional access at the database level

The available levels of nontransactional access are FULL, READ_ONLY, and OFF.

Specify the level of nontransactional access with Transact-SQL

When you create a new database, call the CREATE DATABASE (SQL Server Transact-SQL) statement with the NON_TRANSACTED_ACCESS FILESTREAM option.

CREATE DATABASE database_name
  WITH FILESTREAM ( NON_TRANSACTED_ACCESS = FULL, DIRECTORY_NAME = N'directory_name' );

When you alter an existing database, call the ALTER DATABASE (Transact-SQL) statement with the NON_TRANSACTED_ACCESS FILESTREAM option.

ALTER DATABASE database_name
  SET FILESTREAM ( NON_TRANSACTED_ACCESS = FULL, DIRECTORY_NAME = N'directory_name' );

Specify the level of nontransactional access with SQL Server Management Studio

You can specify the level of nontransactional access in the FILESTREAM Non-transacted Access field of the Options page of the Database Properties dialog box. For more information about this dialog box, see Database Properties (Options Page).

Specify a directory for FileTables at the database level

When you enable nontransactional access to files at the database level, you can optionally provide a directory name at the same time with the DIRECTORY_NAME option. If you don't provide a directory name when you enable nontransactional access, then you have to provide it later before you can create FileTables in the database.

In the FileTable folder hierarchy, this database-level directory becomes the child of the share name specified for FILESTREAM at the instance level, and the parent of the FileTables created in the database. For more information, see Work with Directories and Paths in FileTables.

Specify a directory for FileTables at the database Level

The name that you specify must be unique across the instance for database-level directories.

Specify a directory for FileTables with Transact-SQL

When you create a new database, call the CREATE DATABASE (SQL Server Transact-SQL) statement with the DIRECTORY_NAME FILESTREAM option.

CREATE DATABASE database_name
  WITH FILESTREAM ( NON_TRANSACTED_ACCESS = FULL, DIRECTORY_NAME = N'directory_name' );
GO

When you alter an existing database, call the ALTER DATABASE (Transact-SQL) statement with the DIRECTORY_NAME FILESTREAM option. When you use these options to change the directory name, the database must be exclusively locked, with no open file handles.

ALTER DATABASE database_name
    SET FILESTREAM ( NON_TRANSACTED_ACCESS = FULL, DIRECTORY_NAME = N'directory_name' );
GO

When you attach a database, call the CREATE DATABASE (SQL Server Transact-SQL) statement with the FOR ATTACH option and with the DIRECTORY_NAME FILESTREAM option.

CREATE DATABASE database_name
    FOR ATTACH WITH FILESTREAM ( DIRECTORY_NAME = N'directory_name' );
GO

When you restore a database, call the RESTORE (Transact-SQL) statement with the DIRECTORY_NAME FILESTREAM option.

RESTORE DATABASE database_name
    WITH FILESTREAM ( DIRECTORY_NAME = N'directory_name' );
GO

Specify a directory for FileTables with SQL Server Management Studio

You can specify a directory name in the FILESTREAM Directory Name field of the Options page of the Database Properties dialog box. For more information about this dialog box, see Database Properties (Options Page).

View existing directory names for the instance

To view the list of existing directory names for the instance, query the catalog view sys.database_filestream_options (Transact-SQL) and check the filestream_database_directory_name column.

SELECT DB_NAME ( database_id ), directory_name
    FROM sys.database_filestream_options;
GO

Requirements and restrictions for the database-level directory

  • Setting the DIRECTORY_NAME is optional when you call CREATE DATABASE or ALTER DATABASE. If you don't specify a value for DIRECTORY_NAME, then the directory name remains null. However you can't create FileTables in the database until you specify a value for DIRECTORY_NAME at the database level.

  • The directory name that you provide must comply with the requirements of the file system for a valid directory name.

  • When the database contains FileTables, you can't set the DIRECTORY_NAME back to a null value.

  • When you attach or restore a database, the operation fails if the new database has a value for DIRECTORY_NAME that already exists in the target instance. Specify a unique value for DIRECTORY_NAME when you call CREATE DATABASE FOR ATTACH or RESTORE DATABASE.

  • When you upgrade an existing database, the value of DIRECTORY_NAME is null.

  • When you enable or disable nontransactional access at the database level, the operation doesn't check whether the directory name has been specified, or whether it is unique.

  • When you drop a database that was enabled for FileTables, the database-level directory and all the directory structures of all the FileTables under it are removed.