IBM Mainframe Forum

Hi,

How can we copy records in a PS to a PDS in reverse order without using sort?

Hello,

What is the reason for such a requirement?

I guess you'd have to load the data into a table, then write the data out from the table in reverse order.

Hello,

Or create a table that has record number as the key and retrieve the rows using an ORDER BY ... DESCENDING.

Or define a vsam esds file that uses max-record-number - record-number as the key. The records would be written in reverse order.

And others, but i still wonder why the requirement to accomplish this without using sort. . .

Thanks for the replies.

It was an interview question. he said do it without using a key from a ps to pds.

not sure if reference modification option can work here.

Reference modification would only work within a single record.

Unless you use SORT (either directly through JCL or via a program), in general this cannot be accomplished.

Hello,

It was an interview question. he said do it without using a key from a ps to pds.

Sounds like there is/was some misunderstanding between the people in the room. . . PS and PDS datasets are not "keyed".

Maybe it is me that misunderstands. . .