Comments on: Oracle RDBMS 11gR2 – Solving a Sudoku using Recursive Subquery Factoring http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/ Friends of Oracle and Java Tue, 21 Oct 2014 18:48:09 +0000 hourly 1 http://wordpress.org/?v=4.0 By: Mirek Burnejko http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-6005 Sat, 28 Jan 2012 07:35:41 +0000 http://technology.amis.nl/blog/?p=6404#comment-6005 Great post. Now you can start in an tournament. Anton and his machine.

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By: Dora http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-6004 Fri, 16 Dec 2011 22:22:05 +0000 http://technology.amis.nl/blog/?p=6404#comment-6004 Yesssss!! Now my weekly office sudoku challenges will finally start going my way!!!! :]

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By: jareeq http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-6003 Fri, 07 Oct 2011 08:40:55 +0000 http://technology.amis.nl/blog/?p=6404#comment-6003 Anton this is impressive now you are my third after god and mother :)

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By: Tonny http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-6002 Thu, 11 Aug 2011 12:27:12 +0000 http://technology.amis.nl/blog/?p=6404#comment-6002 set lines 9
before your query you get a nice column like your puzzle.
delete comment #42 :P

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By: Ramesh G http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-6001 Tue, 06 Jul 2010 09:48:55 +0000 http://technology.amis.nl/blog/?p=6404#comment-6001 Wow.. Wonderfull.. Excellent post…

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By: emil http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-6000 Tue, 02 Mar 2010 03:39:38 +0000 http://technology.amis.nl/blog/?p=6404#comment-6000 great post.

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By: Anton Scheffer http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-5999 Mon, 04 Jan 2010 14:53:20 +0000 http://technology.amis.nl/blog/?p=6404#comment-5999 @c: Maybe it suffices to find one solutions, this query finds all solutions.  And that has nothing to do with breadth- or depth-first searching,  that’s because there’s no way to stop the recursion after finding a solution.

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By: C http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-5998 Thu, 31 Dec 2009 20:09:06 +0000 http://technology.amis.nl/blog/?p=6404#comment-5998 It looks to me that what the recursive subquery does is “breadth-first search”, i.e., for each blank square in the sudoku, it considers all possibilities before moving on to the next blank square. That computes all solutions to the sudoku, but I’m wondering if that is a good way of solving a sudoku in practice because it generally suffices to find one solution.

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By: Anton Scheffer http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-5997 Tue, 22 Dec 2009 13:00:25 +0000 http://technology.amis.nl/blog/?p=6404#comment-5997 @W.G. Nice :)
@Bijesh K Recursive subfactoring is something Oracle introduced in 11GR2, so you can’t convert this kind of solutions to 10g.

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By: Bijesh K http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-5996 Tue, 22 Dec 2009 10:12:13 +0000 http://technology.amis.nl/blog/?p=6404#comment-5996 Its brilliant effort, I tried to convert sudoco query in 10g but I am not getting the correct result..Anybody can help me?????

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By: W. G. http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-5995 Sun, 13 Dec 2009 00:41:39 +0000 http://technology.amis.nl/blog/?p=6404#comment-5995 Inspired by your example, I did the Tower of Hanoi:

with h(x, n, a, b, c) as (
select 0, 3, ‘A’, ‘B’, ‘C’ from dual
union all
select x+m*power(2,n), n-1, decode(m, 1, b, a)
, decode(m, 1, a, c), decode(m, 1, c, b)
from h, (select -1 m from dual union all select 1 from dual)
where n > 1
)
select ‘move disk ‘ || n || ‘ from ‘ || a || ‘ to ‘ || c solution
from h order by x
;

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By: Anton Scheffer http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-5994 Fri, 11 Dec 2009 21:28:28 +0000 http://technology.amis.nl/blog/?p=6404#comment-5994 My method solves all sudokus. It’s a brute force solver, so it doesn’t need any clever strategies.

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By: addintel http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-5993 Fri, 11 Dec 2009 14:20:20 +0000 http://technology.amis.nl/blog/?p=6404#comment-5993 how ever this dosen’t resolve all the sudoku types ..maybe just the easy ones.. for a more detailed explanation check this sudoku solver that also contains some strategies used by sudoku experts. http://www.scanraid.com/sudoku.htm . For example i dunno how your algorithm would resolve the Intersection Removal Strategy called also the Pointing Pairs Strategy.

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By: Arnaud Ladrière http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-5992 Wed, 02 Dec 2009 10:55:54 +0000 http://technology.amis.nl/blog/?p=6404#comment-5992 Really amazing !

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By: Cafer http://technology.amis.nl/2009/10/13/oracle-rdbms-11gr2-solving-a-sudoku-using-recursive-subquery-factoring/#comment-5991 Wed, 11 Nov 2009 22:26:47 +0000 http://technology.amis.nl/blog/?p=6404#comment-5991 Very genius Anton! My good friend, ex-colleague :)

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