APT_IO_MAP/APT_IO_NOMAP and APT_BUFFERIO_MAP/APT_BUFFERIO_NOMAP environment variables in DataStage

In many cases memory-mapped I/O contributes to improved performance. However, in certain situations such as a remote disk mounted by way of Network File System (NFS), memory-mapped I/O might cause significant performance problems. Setting the environment variables APT_IO_NOMAP and APT_BUFFERIO_NOMAP to "true" turns off this feature and sometimes affects performance.

AIX® and HP-UX default to NOMAP. Setting APT_IO_MAP and APT_BUFFERIO_MAP to "true" can be used to turn on memory-mapped I/O for these platforms.