Step1 : Concatenate and sort on ur key
step2 : Generate the sequence number and replace ur KEY with it .
the TS request was simply ...
concatenate file1 file2 file 3 and create e unique sequence number
as seen from the example of the output file...
sorting as suggested will mix up the records
so forget about SORTING anything,
any suggestion about sort is ...
1) a misunderstanding of the initial requirement
2) a useless waste of resources in sorting what has already been sorted
( see my previous posts and the replies that follow them )