16.10 - Data Flow - Access Module

Teradata Tools and Utilities Access Module Reference

prodname
Access Module
vrm_release
16.10
created_date
July 2017
category
Programming Reference
featnum
B035-2425-077K

Pipes are bidirectional interprocess communication mechanisms on UNIX, Linux, and Windows systems. They provide input and output file structures accessed by different applications and processes on a first-in-first-out (FIFO) basis.

Using pipes, instead of disk or tape files, provides a substantial performance improvement for data transfer operations between two complementary data extract and load utilities, such as FastExport, FastLoad, and TPump. However, standard pipe mechanisms do not support checkpoint and restart functions because FIFO file structures are not cached, leaving them no way to revert to an earlier position after a system failure or restart. The Teradata Access Module for Named Pipes caches pipe output data stream in a fallback data file that supports checkpoint and restart functions and provides quick, easy recovery from the following:
  • Restarts on the destination database
  • Crashes on the system running the load utility
The Teradata Access Module for Named Pipes does not support checkpoint or restart operations on the source database.
You can use the Teradata Access Module for Named Pipes in the following ways:
  • On UNIX, with client load and unload utilities with the following configurations:
    • Named pipes
    • Unnamed pipes and file descriptor devices
    • Teradata Parallel Transporter
  • On Windows