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Subject: Re: Do top programs use 64 bit hash signature?

Author: Dann Corbit

Date: 10:44:52 12/10/99

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On December 10, 1999 at 09:03:43, Robert Hyatt wrote:
[snip]
>I don't see the connection between hash signature and table size. I use a 64
>bit signature, which means I can use _any_ table size up to 2^64...  I can even
>go beyond 2^64 entries by using what is commonly called 'buckets'.  (A bucket is
>a set of entries rather than a single entry.  Then I would probe to a specific
>bucket.  I would need some way to differentiate between the different positions
>that produce the same hash signature for that bucket of course, if I use 2^64
>buckets or more..)
If you store the whole 64 bits "somewhere" (even though you only use a fragment
for the lookup) then the bigger the hash, the fewer the entries you can hold.
If you don't store the full 64 bits somewhere, then you don't really have a 64
bit hash.  You have only the bits that actually get stored when you check for
collision.



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