#2 is the best option, hands down. Everything else is crushing peanuts with an elephant's hoof, IMO. If you want to do it inside SAS, #1 is preferred. A simple "data xxx; set yyy; run;" will not be slower than #3, because it will be simply limited by I/O bandwidth. Hint: Copying inside the same library will usually be slower than copying to another one, because you use the same HW for reading and writing. Different libs _may_ be located on different disks, giving you more aggregate bandwidth.
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