Perhaps the answer isn't so complicated. It would be crazy to do a full-content comparison across your whole database, but it will probably be sufficient to single out a few special cases and likely aliases and just test for those. in the case you mention - www.foo.com eq foo.com - it would be very easy to look out for just that pair and checksum the two pages to make sure they differ.

incidentally, since you're doing something clever and complicated to the content of each item later on anyway, perhaps you'd be better off just grabbing everything and deferring redundancy checks until you start munching it up?

in other words, my .02p says this situation requires laziness, not hubris.

In reply to Re: Eliminating "duplicate" domains from a hash/array by thpfft
in thread Eliminating "duplicate" domains from a hash/array by hacker

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