That's a really interesting idea.

In this case I'm not sure its workable as, unlike my example, the integers in question can potentially take the full (unsigned) range of values--they are in fact addresses--so the bit vectors could get pretty large.

Even if I scale the values (the addresses will always be at least 4-byte aligned), the range is still potentially 2**29 on a 32-bit cpu, which would make for some pretty sparse bitvectors. RLE might help, but then you loose the advantage of being able to use bitstring logical operations on them.

Later on I might be able to fursther reduce the range by excluding a large chunks at the bottom (and maybe top) of memory, and I might be able to rely on 12 or even 16 byte alignment. That would hugely reduce the size of the bitvectors and coud bring this into the realms of feasability. Thanks.

If anyone knows of how to obtain the lower and upper bounds of the dynamic memory of the current Perl process, I'd love to hear from them.

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In reply to Re^2: Searching parallel arrays. by BrowserUk
in thread Searching parallel arrays. by BrowserUk

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