Author: Inmann Werner
Date: 14:45:39 10/19/99
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On October 19, 1999 at 07:47:56, Robert Hyatt wrote: >it is simply the 64 bit hash signature... I use the rightmost N bits as the >probe address, and store the entire 64 bit signature as the 'checksum' as you >call it... > >>My question is: with, at most, 128bits per position (that I'll never would use >>in fact), isn't it possible to make mistakes? I know the probability is small, >>but eventually there could be a very strange move coming from a hash table >>mistake. Is this true? What am I missing? > >mistakes are possible. But they are _very_ improbable using 64 bits. The >way to confirm this is to have a debug mode where you do store the simple 256 >bit actual board position. When you get a match on the 64 bit value, then >check the full 256 bit value. If it doesn't match, you have a false match. I >ran such a test for many hours and got zero. > >>Is, anyway, safe to use a 64bit checksum? And if so, is the checksum generated >>the same way as the hash code, but with different random numbers? > Do we really need a 64 bit checksum? How much risk a 32 bit checksum would be, you think? Werner
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