No, but mergesort can easily fall back to dumping its sorted contents to disk, for later merging; this disk-based merge sort was invented by van Neumann in the

No, but mergesort can easily fall back to dumping its sorted contents to disk, for later merging; this disk-based merge sort was invented by van Neumann in the 1940s, and is how the unix utility sort works (dozen-way merge of sorted shards of a file).