as already told gazillions times... it cannot be done ( the reading )
please explain better about the write
to process backwards You will have to <sort> in reverse order using a real / virtual sequence key and sort again in the original sequence
but if the need is <real> the process should be revisited
cheers enrico When I tell somebody to RTFM or STFW I usually have the page open in another tab/window of my browser, so that I am sure that the information requested can be reached with a very small effort
What an idiot I can be! Of course you write to the "bottom" of a sequential data set!
As for reading from the end of a sequential data set, write it to tape and then reread the tape in backwards mode. Or, as enrico-sorichetti said, sort it into reverse order to a new data set and read the new data set normally.