This is a standard trick.

Yes. And it requires 4 passes of the dataset, including two full sorts.

And takes 5 or 6 times as long as the script above, if I use 5 passes ('a-e','f-j', 'k-o', 'p-t', 'u-z') on the same dataset.

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
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In the absence of evidence, opinion is indistinguishable from prejudice.
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In reply to Re^3: Huge files manipulation by BrowserUk
in thread Huge files manipulation by klashxx

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