Use these parameters to enable and disable use of the Direct NFS Client on input data files during an external tables operation.
The Direct NFS Client is an API that can be implemented by file servers to allow improved performance when Oracle accesses files on those servers.
External tables uses the Direct NFS Client interfaces by default when it reads data files over 1 gigabyte. For smaller files, the operating system's I/O interfaces are used. To use the Direct NFS Client on all input data files, use DNFS_ENABLE.
To disable use of the Direct NFS Client for all data files, specify DNFS_DISABLE.
Oracle Grid Infrastructure Installation Guide for Linux for information about enabling Direct NFS Client Oracle Disk Manager Control of NFS