.file extension BTX - SEEDIS index file
File extension BTX description:
BTXMAKE makes a b+tree file from the SEEDIS style DDF or EDF files for use in the SEEDIS programs. The resultant output file, which has the extension *.btx, replaces the DDX or EDX file and has the advantage of speedier look-up in those programs using data definition files. The BTX file does not have data stored in it but rather points to records in the DDF/EDF files.