Delegating it to sort - be it the shell command or the Perl built-in - is a waste of resources, which doesn't scale well.

Except of course once the hash has become too large for memory. Then a disk-based mergesort (well, mergecount maybe) is the only thing that will still scale, provided that you have enough disk space to write the merged results.

In reply to Re^3: Out of Memory when generating large matrix by Corion
in thread Out of Memory when generating large matrix by cathyyihao

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