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Subject: Re: Binary Book Creation

Author: Gian-Carlo Pascutto

Date: 04:11:58 06/19/00

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On June 19, 2000 at 06:03:43, Adrien Regimbald wrote:

>Also - rather than simply dumping the hash table I used to make the book with
>into a binary file and using that, I simply looped through all actual positions
>which occured (I culled out any moves occuring only once), and wrote each
>position to the binary file - you can see the difference - only 380 K for 40 >ply rather than 24 MB!

I also loop through all games/moves, writing out each position to a binary
hashed database (I use the GDBM library). Once I'm done looping the games,
I loop through all positions in the database and cull out everything that
isnt't played at least 3 times.

Somed data: a 34MB PGN database of PGN games leads to a 47MB database on
the first pass, which is reduced to 3.7MB after the second pass.

Crafty's book for the same games and with the same parameters is only 1.3M.

I wonder how this is possible, considering that I don't store as much data
per position. (only a times played long int). Maybe GDBM isn't as efficient
as it claims to be?

My main problem right now is speed...it takes redicolously long to parse in
all PGN (darn my parser is slow) and GDB slows down due to disk accesses when
the database gets big (still smaller than physical RAM though...so I dont
get why it does).

>Incidentally - I don't have enough web space to put up the PGN file I used to
>make the book, or a swack of PGN files for you to make books with either, so ..
>what would be your preference for the default book?  I'm thinking 30 ply..

If you are in need of webspace, I can give you the password for Sjeng's ftp/web
space on sourceforge and you can put it up there. It's a very fast server and
you can have up to 200Megs.

>So - expect an official release of Faile 1.4 sometime within the next week (the
>length of time this takes depends on how fast I can get some testing done.. :P)

If you have no objections to it, I'll incorporate any usefull improvements
into Sjeng too.

--
GCP



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