It is indeed. Thank you very much. I pack as follows though: 
my $p = pack('L*', @$pa);

[download]
because it's an integer array.
I also think it uses less memory. But that I still have test.
Thanks again. Seems like this is the only thing to do apart from implementing my own hash algorithm.

In reply to Re^2: non-scalar hash key by kdejonghe
in thread non-scalar hash key by kdejonghe

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