When the DataLink column is created as FILE LINK CONTROL level with file system (FS) permissions, the system will verify that any DataLink value is a valid URL, with a valid server name and file name.
The file must exist at the time that row is being inserted into the SQL table. When the object is found, it will be marked as linked. This means that the object cannot be moved, deleted, or renamed during the time that it is linked. Also, an object cannot be linked more than once. If the server name portion of the URL specifies a remote system, that system must be accessible. If a row containing a DataLink value is deleted, the object is unlinked. If a DataLink value is updated to a different value, the old object is unlinked, and the new object is linked.
The integrated file system is still responsible for managing permissions for the linked object. The permissions are not modified during the link or unlink processes. This option provides control of the object's existence for the duration of time that it is linked.