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Subject: Re: question about hash tables

Author: Brian Richardson

Date: 19:04:05 05/07/02

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On May 07, 2002 at 13:34:34, Robert Hyatt wrote:
>Nothing wrong with starting simple.  Always store entries in the normal search,
>don't in the q-search.  It will be easy to add it to the q-search later if you
>think you want to try it...
>
>A single always-replace table will not be anywhere near as good as the two-table
>approach most of us use (one is always replace, the other is replace with deeper
>draft only).

I have tested this several times with Tinker.  In nearly all cases a single
table (replacing when id is different, or based on depth when the same) does
better than the 2 table approach.  Some of the tests in ICCA are based on much
older systems with smaller main memory sizes.  I think with modern memory sizes
and hash tables much greater than 1 million entries, things change.  Tinker
usually runs with 32M entries.

In any case, you may want to try both 1 table and 2 in your program, since each
search is somewhat different.  For example, hashing q-search entries is also
faster for Tinker, but apparently not for Crafty.





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