Combine data sets-which is the fastest method?

[mei]

Dear Patrick

The output turns out well, the truncation warning no more appear!! Thanks

But there is an additional note: I hope it is fine.

NOTE: The query requires remerging summary statistics back with the original data.

[mei]

hi Patrick

I noted that the variables in the output from your program has turned out to appear in alphabetical order.

How do i get an output that appear in the same format of the original datasets in terms of its sequence of its columns?

thanks