Search found 152 matches

by Dave_N
Fri Apr 13, 2012 2:39 am
Forum: Computer Chess Club: General Topics
Topic: Computer code Is not property and can’t b stolen
Replies: 36
Views: 4638

Re: Computer code Is not property and can’t b stolen

I think source code is property and the contents of an individuals hard drive are property. The reasons are quite clear 1) If person B takes source code (by whatever method) from person A and then takes the source code and builds the software and completes the project before the original author (usi...
by Dave_N
Sun Mar 11, 2012 5:51 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Database storage methods
Replies: 37
Views: 6548

Re: Database storage methods

Well the legal moves seem ok at this stage, I found some bugs while compressing large files. I think I am failing to appreciate some of the finer qualities of Zobrist hash, perhaps a hash table / tree lookup system saying "white pawn on e4 and black Queen on a8" using a tree of hash elements, (an in...
by Dave_N
Sun Mar 11, 2012 5:08 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Database storage methods
Replies: 37
Views: 6548

Re: Database storage methods

An idea I got from the other thread about database methods, is that after I make a hash set for the lines that merge the most (e4 c5 etc) most of the games can store fewer moves and the index of their root game, so they can save some bytes. Perhaps then looking at the positions generated and writing...
by Dave_N
Sun Mar 11, 2012 4:49 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Database storage methods
Replies: 37
Views: 6548

Re: Database storage methods

I am thinking about Storing a compressed move list as a Tree in a hash table ... The hash entry obviously has the following int64 hash int addrNext; // if needing a mainline int addrVariation; then for each move the game is merged by putting all variations found in a linked list of hash entries, so...
by Dave_N
Fri Mar 09, 2012 6:02 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: New Database Storage Method
Replies: 13
Views: 2586

Re: New Database Storage Method

I think I'm planning to store the range of sorted list of games that pass through the position in the hash node. And pointers. I think it wouldn't fit entirely in RAM.
by Dave_N
Thu Mar 08, 2012 8:51 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Database storage methods
Replies: 37
Views: 6548

Re: Database storage methods

The discussion would not be complete without this link: http://www.gotw.ca/gotw/072.htm "Data Formats and Efficiency. How good are you at choosing highly compact and memory-efficient data formats? How good are you at writing bit-twiddling code? This GotW gives you ample opportunity to exercise both...
by Dave_N
Thu Mar 08, 2012 8:48 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Database storage methods
Replies: 37
Views: 6548

Re: Database storage methods

Perhaps, however how can this method handle very large Databases (>10million games) ?
by Dave_N
Thu Mar 08, 2012 5:03 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Database storage methods
Replies: 37
Views: 6548

Re: Database storage methods

I am not sure what problem you try to solve here. In a collection of games almost all positions will occur in only a single game. So there is not a huge gain in terms of number of positions when you cllapse multiply occurring (opening) positions to one. If combining involves some overhead, like ext...
by Dave_N
Thu Mar 08, 2012 1:32 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Database storage methods
Replies: 37
Views: 6548

Re: Database storage methods

I thought about this - the problem of searching for tree lines that can transpose must occur in Hippo style positions, with many transposable lines. without captures or moving the same piece twice there must be [ply ! ] number of lines to search, this becomes very time consuming I guess. Maybe there...
by Dave_N
Thu Mar 08, 2012 12:43 pm
Forum: Computer Chess Club: Programming and Technical Discussions
Topic: Database storage methods
Replies: 37
Views: 6548

Re: Database storage methods

One compression idea is to store a move (usually 2 bytes, or 2x6=12 bits) as an 8-bit number representing the number in the pseudo-legal move generation list. Takes a lot of extra processor time but saves disk space. Right. In ICCA's January 1983 Newsletter, Kathe Spracklen (co-author of Sargon) wr...