Daniel Lemire

3 mars 2018

Un autre blogue que je recommande fortement est celui de Daniel Lemire (pas l’humoriste mais bien l’informaticien!).  Il y traite souvent d’algorithmes et de performance avec une minutie du détail inouïe.

Pour avoir un bon exemple de son style et des sujets qu’il traite, je vous suggère son billet sur le choix aléatoire de nombre distinct (Picking distinct numbers at random: benchmarking a brilliant algorithm) ainsi que son article intitulé Iterating over set bits quickly.

Finalement, un exemple de ses contributions à l’open source, les RoaringBitmap.

 

 


MySQL, restore et performance!

28 février 2018

Une analyse sérieuse des façons d’optimiser la vitesse d’un RESTORE en MySQL.


Group by de 4 manières

12 février 2018

Différentes subtilités du GROUP BY en MySQL expliquées pour chacune des 4 versions.  Variations sur un même thème expliquées ici!


That guy

3 avril 2017

We all know that guy. You know, that guy who sees performance improvements everywhere, all the time?

That programmer who squeezes everything into bitmaps because « it’s so much faster » ?  And when I say everything, I mean everything! Even if your class only has one flag!

That guy who caches everything in the application because « that’s the optimal way to do it« ?  Even if the data that is cached is just accessed only one time?

That guy who fits a date into an integer in the database because « it’s so much more compact » ?  There goes all your SQL and date functions!

That developer who always ends up re-implementing another sorting algorithm because he read a « great paper » on the subject and « it’s proven that it’s 0.2% faster than the default sort » available?  And after an insane debugging session, you finally realize he has overriden SortedCollection>>#sort: ?  And that his code just doesn’t work properly!

You know, that guy with a C/C++ background who spends countless hours optimizing everything not realizing he has to « make it work » first! You know, that guy who still doesn’t get that often times you only need to optimize very small parts of an application to make a real difference?

You know that guy with strange concepts such as « defensive programming » who tells you nobody ever caught a bug in his code in production? You know, that guy who came up with the « clever » catch-everything method #ifTrue:ifFalse:ifNil:onError:otherwise: ?

You know that guy who never works for more than 4 months at the same place because « they didn’t get it, they’re a bunch of morons » ?

You know, that guy who prefers to implement complex database queries with a #do: loop and a gazillion SELECT statement because « SELECT statements with a 1-row lookup are very optimized by the database server » instead of using JOINs. And then he blames the slow response time of his « highly optimized » data retrieval code on the incompetence of the DBAs maintaining the database?

You know, that guy who once told me « inheritance in Smalltalk is very bad because the deeper the class in the hierarchy, the slower the method lookup is going to be » so that’s why he always preferred « flattened hierarchies » (meaning promoting ALL instance variables into one root class) with 2-3 levels deep in the worst case? « Besides, my code is easier to understand and debug since everything is in one place« .

Well, I was going through some of the sh*ttiest code I’ve seen in a long time last night and I remembered that guy and his ideas about « highly optimized flattened hierarchies » and thought I’d measure his theory!  Here’s the script.

Basically, it creates a hierarchy of classes (10000 subclasses) and times message sends from the top class and the bottom class to measure the difference.

Well, that guy was right… There’s a 1 millisecond difference over 9 million message sends from the root class as compared to the 10000th class at the bottom of the hierarchy.

I wanted to tell that guy he was right but his email address at work is probably no longer valid…

CAVEAT: Make sure you do not have a category with the same name as the one in the script because the script removes the category at the end (and all classes in it!).  Also, be warned it takes a very very very long time to execute!

P.S. All the stories above are real. No f*cking kidding!  Those guys really existed : I’ve worked with them!


La performance de votre queue

19 mars 2017

Ça y est?  J’ai toute votre attention? :)

Ces temps-ci je planche sur un problème relié à la performance de queues de messages (file d’attente de messages, file de messages, message queue).  Heureusement, plutôt que d’avoir à expérimenter par essais et erreurs ou à simuler le système final, les mathématiques sont venues à la rescousse.

Deux articles hyper-utiles sur la performance des queues de messages : le premier ici et le second ici.

Et pour ceux que ça intéresse, il est également possible de télécharger gratuitement un document PDF sur le sujet ici.


Compiler magic

22 février 2017

How do you efficiently divide by 19? All you need is some compiler magic!  It’s all explained here!


InnoDb variables

9 septembre 2016

Sure, there are tools and script to help you fine tune your MySQL server but there’s nothing like using your brain.

Pythian has done a wonderful job of explaining what all those InnoDb-related variables in a series of articles…

Exposing Innodb Internals via System Variables: Part 1, Memory
Exposing Innodb Internals via System Variables: Part 2, I/O (structure and logs)
Exposing Innodb Internals via System Variables: Part 3, I/O (Table data)
Exposing Innodb Internals via System Variables: Part 4, Concurrency
Exposing Innodb Internals via System Variables: Part 5, Consistency / Statistics handling


Mesurer la performance

27 mai 2014

Si vous êtes contraint de mesurer la performance de votre application en Smalltalk, bien que les outils de profilage disponibles suffisent habituellement à la tâche, il arrive qu’on doive recourir aux bonnes vieilles méthodes.


Comment presser un citron (troisième partie)

27 mai 2013

1. Un problème n’arrive jamais seul

Dans la deuxième partie de cet article (le premier article étant ici), nous nous sommes laissés sur un exemple extrême (i.e. une grille avec des lignes et des colonnes vides) afin de vérifier la validité et l’efficacité de la solution présentée dans un des pires scénarios envisageable :

Avant même de débuter, rappelez-vous qu’il est primordial d’exécuter la commande suivante dans votre session pour éviter d’avoir à attendre une éternité, que ce soit pour la requête SQL ou pour un EXPLAIN!

set @@optimizer_search_depth = 3;

Qu’arriverait-il si nous avions à solutionner un sudoku contenant à la fois des lignes et des colonnes vides, comme dans l’exemple ci-haut avec la requête suivante:

SELECT *
FROM sudoku_combined_view
WHERE
(r2c2 = 3) AND (r2c3 = 4) AND (r2c4 = 8) AND (r2c5 = 2) AND
(r2c6 = 5) AND (r2c7 = 6) AND (r2c8 = 9) AND (r3c2 = 5) AND
(r3c3 = 9) AND (r3c4 = 3) AND (r3c5 = 6) AND (r3c6 = 4) AND
(r3c7 = 1) AND (r3c8 = 8) AND (r4c2 = 9) AND (r4c3 = 7) AND
(r4c4 = 1) AND (r4c5 = 8) AND (r4c6 = 2) AND (r4c7 = 5) AND
(r4c8 = 6) AND (r6c2 = 8) AND (r6c3 = 1) AND (r6c4 = 4) AND
(r6c5 = 7) AND (r6c6 = 6) AND (r6c7 = 2) AND (r6c8 = 3) AND
(r7c2 = 2) AND (r7c3 = 5) AND (r7c4 = 6) AND (r7c5 = 4) AND
(r7c6 = 1) AND (r7c7 = 9) AND (r7c8 = 7) AND (r8c2 = 7) AND
(r8c3 = 6) AND (r8c4 = 5) AND (r8c5 = 3) AND (r8c6 = 8) AND
(r8c7 = 4) AND (r8c8 = 2);

Examinons le résultat du EXPLAIN pour la grille en question:

+----+-------------+-------+-------------+----------------------------------------------------------------------------------------------------------------------------------------------------+-------------+---------+-------------------------------+------+----------------------------------------------------------+
| id | select_type | table | type        | possible_keys                                                                                                                                      | key         | key_len | ref                           | rows | Extra                                                    |
+----+-------------+-------+-------------+----------------------------------------------------------------------------------------------------------------------------------------------------+-------------+---------+-------------------------------+------+----------------------------------------------------------+
|  1 | SIMPLE      | col3  | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i23,i38,i48 | 2,2,2   | NULL                          |   64 | Using intersect(i23,i38,i48); Using where                |
|  1 | SIMPLE      | r2    | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i23,i58     | 2,2     | NULL                          |   68 | Using intersect(i23,i58); Using where; Using join buffer |
|  1 | SIMPLE      | r3    | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i78,i56     | 2,2     | NULL                          |   68 | Using intersect(i78,i56); Using where; Using join buffer |
|  1 | SIMPLE      | r4    | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i38,i46     | 2,2     | NULL                          |   68 | Using intersect(i38,i46); Using where; Using join buffer |
|  1 | SIMPLE      | r6    | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i23,i67     | 2,2     | NULL                          |   68 | Using intersect(i23,i67); Using where; Using join buffer |
|  1 | SIMPLE      | r7    | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i38,i56     | 2,2     | NULL                          |   68 | Using intersect(i38,i56); Using where; Using join buffer |
|  1 | SIMPLE      | r8    | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i23,i68     | 2,2     | NULL                          |   68 | Using intersect(i23,i68); Using where; Using join buffer |
|  1 | SIMPLE      | col2  | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i23,i68     | 2,2     | NULL                          |   68 | Using intersect(i23,i68); Using where; Using join buffer |
|  1 | SIMPLE      | col4  | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i78,i46     | 2,2     | NULL                          |   68 | Using intersect(i78,i46); Using where; Using join buffer |
|  1 | SIMPLE      | col5  | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i23,i68     | 2,2     | NULL                          |   68 | Using intersect(i23,i68); Using where; Using join buffer |
|  1 | SIMPLE      | col6  | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i23,i67     | 2,2     | NULL                          |   68 | Using intersect(i23,i67); Using where; Using join buffer |
|  1 | SIMPLE      | col7  | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i23,i68     | 2,2     | NULL                          |   68 | Using intersect(i23,i68); Using where; Using join buffer |
|  1 | SIMPLE      | col8  | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i37,i24     | 2,2     | NULL                          |   68 | Using intersect(i37,i24); Using where; Using join buffer |
|  1 | SIMPLE      | col1  | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i23         | 2       | sudoku.r2.c1,sudoku.r3.c1     | 5040 | Using where                                              |
|  1 | SIMPLE      | r1    | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i12         | 2       | sudoku.col1.c1,sudoku.col2.c1 | 5040 | Using where                                              |
|  1 | SIMPLE      | r5    | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i12         | 2       | sudoku.col1.c5,sudoku.col2.c5 | 5040 | Using where                                              |
|  1 | SIMPLE      | r9    | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i12         | 2       | sudoku.col1.c9,sudoku.col2.c9 | 5040 | Using where                                              |
|  1 | SIMPLE      | col9  | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i12         | 2       | sudoku.r1.c9,sudoku.r2.c9     | 5040 | Using where                                              |
+----+-------------+-------+-------------+----------------------------------------------------------------------------------------------------------------------------------------------------+-------------+---------+-------------------------------+------+----------------------------------------------------------+
18 rows in set (0.20 sec)

À première vue, tout semble correct! Aucun table scan et les indexes sont utilisés pour chaque colonne et chaque rangée non vide!

Et en combien de temps MySQL peut-il « solutionner » cette grille ?

Fantastique!  1.5 seconde!  Tout est réglé!  Malheureusement, non…

2. Le pire scénario possible

Il existe une catégorie de sudokus que nombre de mathématiciens et d’informaticiens étudient depuis des années : ces grilles minimales n’ont seulement que 17 révélés, le minimum théorique (une conjecture encore non prouvée de façon mathématique par Gary McGuire, Bastian Tugemann et Gilles Civario, un autre intéressant article ici) pouvant mener à une solution unique.  Plusieurs de ces grilles spéciales (17 révélés) sont depuis des années compilées par Gordon Royle, professeur à l’université d’Australie Occidentale.

Comme celle-ci :

Vous remarquerez que cette grille ne contient aucune ligne ni aucune colonne vide! Essayons donc de voir en combien de temps MySQL pourra résoudre celle-ci :

mysql> SELECT *
 -> FROM sudoku_combined_view
 -> WHERE
 -> (r1c8 = 1) AND
 -> (r2c1 = 4) AND
 -> (r3c2 = 2) AND
 -> (r4c5 = 5) AND
 -> (r4c7 = 4) AND
 -> (r4c9 = 7) AND
 -> (r5c3 = 8) AND
 -> (r5c7 = 3) AND
 -> (r6c3 = 1) AND
 -> (r6c5 = 9) AND
 -> (r7c1 = 3) AND
 -> (r7c4 = 4) AND
 -> (r7c7 = 2) AND
 -> (r8c2 = 5) AND
 -> (r8c4 = 1) AND
 -> (r9c4 = 8) AND
 -> (r9c6 = 6);
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
| r1c1 | r1c2 | r1c3 | r1c4 | r1c5 | r1c6 | r1c7 | r1c8 | r1c9 | r2c1 | r2c2 | r2c3 | r2c4 | r2c5 | r2c6 | r2c7 | r2c8 | r2c9 | r3c1 | r3c2 | r3c3 | r3c4 | r3c5 | r3c6 | r3c7 | r3c8 | r3c9 | r4c1 | r4c2 | r4c3 | r4c4 | r4c5 | r4c6 | r4c7 | r4c8 | r4c9 | r5c1 | r5c2 | r5c3 | r5c4 | r5c5 | r5c6 | r5c7 | r5c8 | r5c9 | r6c1 | r6c2 | r6c3 | r6c4 | r6c5 | r6c6 | r6c7 | r6c8 | r6c9 | r7c1 | r7c2 | r7c3 | r7c4 | r7c5 | r7c6 | r7c7 | r7c8 | r7c9 | r8c1 | r8c2 | r8c3 | r8c4 | r8c5 | r8c6 | r8c7 | r8c8 | r8c9 | r9c1 | r9c2 | r9c3 | r9c4 | r9c5 | r9c6 | r9c7 | r9c8 | r9c9 |
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
|   6  |   9  |   3  |   7  |   8  |   4  |   5  |   1  |   2  |   4  |   8  |   7  |   5  |   1  |   2  |   9  |   3  |   6  |   1  |   2  |   5  |   9  |   6  |   3  |   8  |   7  |   4  |   9  |   3  |   2  |   6  |   5  |   1  |   4  |   8  |   7  |   5  |   6  |   8  |   2  |   4  |   7  |   3  |   9  |   1  |   7  |   4  |   1  |   3  |   9  |   8  |   6  |   2  |   5  |   3  |   1  |   9  |   4  |   7  |   5  |   2  |   6  |   8  |   8  |   5  |   6  |   1  |   2  |   9  |   7  |   4  |   3  |   2  |   7  |   4  |   8  |   3  |   6  |   1  |   5  |   9  |
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
1 row in set (2 min 20.83 sec)

Ouch!  Je ne suis pas arrivé à descendre sour la barre des 40 secondes malgré mes tentatives répétées et ce, sur différents serveurs avec différentes configurations (et même différentes autres grilles de 17 révélés). Les résultats pour solutionner cette grille vont de près de 40 secondes à plus de 33 minutes. Le résultat du EXPLAIN parle par lui-même :

+----+-------------+-------+-------------+----------------------------------------------------------------------------------------------------------------------------------------------------+---------+---------+-------------------------------+------+----------------------------------------------------------+
| id | select_type | table | type        | possible_keys                                                                                                                                      | key     | key_len | ref                           | rows | Extra                                                    |
+----+-------------+-------+-------------+----------------------------------------------------------------------------------------------------------------------------------------------------+---------+---------+-------------------------------+------+----------------------------------------------------------+
|  1 | SIMPLE      | r4    | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i57,i59 | 2,2     | NULL                          |  624 | Using intersect(i57,i59); Using where                    |
|  1 | SIMPLE      | r7    | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i14,i47 | 2,2     | NULL                          |  624 | Using intersect(i14,i47); Using where; Using join buffer |
|  1 | SIMPLE      | col4  | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i78,i89 | 2,2     | NULL                          |  624 | Using intersect(i78,i89); Using where; Using join buffer |
|  1 | SIMPLE      | col7  | index_merge | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i45,i47 | 2,2     | NULL                          |  624 | Using intersect(i45,i47); Using where; Using join buffer |
|  1 | SIMPLE      | r8    | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i24     | 2       | const,const                   | 5000 | Using where                                              |
|  1 | SIMPLE      | r9    | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i46     | 2       | const,const                   | 5001 | Using where                                              |
|  1 | SIMPLE      | col1  | range       | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i27     | 2       | NULL                          | 5000 | Using where; Using join buffer                           |
|  1 | SIMPLE      | r5    | range       | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i37     | 2       | NULL                          | 5001 | Using where; Using join buffer                           |
|  1 | SIMPLE      | r6    | range       | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i35     | 2       | NULL                          | 5001 | Using where; Using join buffer                           |
|  1 | SIMPLE      | col3  | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i45     | 2       | sudoku.r4.c3,const            | 5040 | Using where                                              |
|  1 | SIMPLE      | col2  | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i34     | 2       | const,sudoku.r4.c2            | 5040 | Using where                                              |
|  1 | SIMPLE      | r2    | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i12     | 2       | const,sudoku.col2.c2          | 5040 | Using where                                              |
|  1 | SIMPLE      | col5  | range       | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i46     | 2       | NULL                          | 5001 | Using where; Using join buffer                           |
|  1 | SIMPLE      | r3    | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i12     | 2       | sudoku.col1.c3,const          | 5040 | Using where                                              |
|  1 | SIMPLE      | col8  | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i12     | 2       | const,sudoku.r2.c8            | 5040 | Using where                                              |
|  1 | SIMPLE      | r1    | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i12     | 2       | sudoku.col1.c1,sudoku.col2.c1 | 5040 | Using where                                              |
|  1 | SIMPLE      | col9  | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i12     | 2       | sudoku.r1.c9,sudoku.r2.c9     | 5040 | Using where                                              |
|  1 | SIMPLE      | col6  | ref         | i12,i13,i14,i15,i16,i17,i18,i19,i23,i24,i25,i26,i27,i28,i29,i34,i35,i36,i37,i38,i39,i45,i46,i47,i48,i49,i56,i57,i58,i59,i67,i68,i69,i78,i79,i89,i9 | i12     | 2       | sudoku.r1.c6,sudoku.r2.c6     | 5040 | Using where                                              |
+----+-------------+-------+-------------+----------------------------------------------------------------------------------------------------------------------------------------------------+---------+---------+-------------------------------+------+----------------------------------------------------------+
18 rows in set (2.59 sec)

Observez la colonne rows dans le résultat du EXPLAIN pour comprendre le nombre astronomique de jointures possibles que MySQL aura à effectuer et à tester…  Dans la très grande majorité des cas, ce chiffre est supérieur à 5000!

Il devient maintenant évident que notre solution ne tient plus la route…

3. Ne pas céder au découragement!

Il existe bon nombre d’autres possibilités d’optimisations que nous n’avons toujours pas envisagées.  Par exemple, dans certains cas il pourrait être avantageux de chercher par boîtes (carré de 3×3 dans le sudoku).  Certaines grilles de 17 révélés pourraient grandement en bénéficier mais il nous faudrait alors joindre 27 tables!  Ce qui est gagné d’un côté est perdu de l’autre.

Nous pourrions également créer des partitions mais dans ce cas, quelles seraient les chances qu’une colonne ou une rangée contienne la donnée permettant de discriminer et de choisir la partition requise?

Nous pourrions augmenter la taille de l’index pour passer de 2 colones à 3 mais l’impact de cette mesure serait inutile pour les grilles de 17 révélés.

Qu’arriverait-il si nous passions du format de table MyISAM à InnoDb ?  Absolument rien, le problème demeure entier : MySQL n’est pas assez rapide pour lire les données (ou les indexes) sur disque puis les joindre efficacement dans un cas aussi extrême.

L’idée à la base de cette série d’article était d’arriver à solutionner un sudoku valide en n’utilisant que du SQL.  Un sudoku valide, par définition, a une seule solution.  Nous aurions pu ajouter LIMIT 1 à chacune de nos vues mais hélas, ce faisant, nos vues seraient contraintes d’utiliser l’algorithme TEMPTABLE au lieu de MERGE, ce qui serait catastrophique!

Évidemment, quelques autres astuces existent, comme augmenter la taille des variables key_buffer_size et join_buffer_size, diminuer la valeur du optimizer_search_depth, etc.  Évidemment dans le cas des 2 premières variables, je ne peux rien vous suggérer comme ces paramètres dépendent de la mémoire RAM disponible sur votre machine, le système d’exploitation utilisé, etc.  Quant à la valeur de la variable optimizer_search_depth, diminuer celle-ci n’aura pas d’impact significatif comme le problème réside dans la lenteur des accès au disque dur et au nombre effarant de jointures et de rangées à examnier (et à retrouver puis lire).

4. Éplucher toutes les options

Il existe un type de table, MEMORY, en MySQL qui nous permettrait d’éviter d’avoir à lire les données (ou les indexes) sur disque, ce qui pourrait avoir un impact majeur dans notre cas.  Nous allons donc créer cette table en mémoire et la remplir tout en créant les indexes nécessaires (exactement les mêmes vues et indexes que la table de format MyISAM).

Mais avant de procéder, prenez bien soin de vous assurez que la variable max_heap_table_size soit supérieure à 216Mb ( 226492416) sinon vous vous heurterez à une tonne d’erreurs 1114 (table full).  Si ce n’est pas le cas, vous pouvez fixer la valeur de cette variable à 216Mb comme suit :

set @@max_heap_table_size =  226492416;

Une fois cette précaution prise, construisez la table et les indexes nécessaires comme suit:

USE sudoku;

DROP TABLE IF EXISTS positions_memory;
CREATE TABLE positions_memory (
 c1 TINYINT UNSIGNED NOT NULL,
 c2 TINYINT UNSIGNED NOT NULL,
 c3 TINYINT UNSIGNED NOT NULL,
 c4 TINYINT UNSIGNED NOT NULL,
 c5 TINYINT UNSIGNED NOT NULL,
 c6 TINYINT UNSIGNED NOT NULL,
 c7 TINYINT UNSIGNED NOT NULL,
 c8 TINYINT UNSIGNED NOT NULL,
 c9 TINYINT UNSIGNED NOT NULL
) ENGINE=MEMORY;

INSERT INTO positions_memory (c1, c2, c3, c4, c5, c6, c7, c8, c9)
SELECT c1, c2, c3, c4, c5, c6, c7, c8, c9 FROM positions;

CREATE INDEX i12 ON positions_memory(c1, c2) USING HASH; CREATE INDEX i13 ON positions_memory(c1, c3) USING HASH;
CREATE INDEX i14 ON positions_memory(c1, c4) USING HASH; CREATE INDEX i15 ON positions_memory(c1, c5) USING HASH;
CREATE INDEX i16 ON positions_memory(c1, c6) USING HASH; CREATE INDEX i17 ON positions_memory(c1, c7) USING HASH;
CREATE INDEX i18 ON positions_memory(c1, c8) USING HASH; CREATE INDEX i19 ON positions_memory(c1, c9) USING HASH;
CREATE INDEX i23 ON positions_memory(c2, c3) USING HASH; CREATE INDEX i24 ON positions_memory(c2, c4) USING HASH;
CREATE INDEX i25 ON positions_memory(c2, c5) USING HASH; CREATE INDEX i26 ON positions_memory(c2, c6) USING HASH;
CREATE INDEX i27 ON positions_memory(c2, c7) USING HASH; CREATE INDEX i28 ON positions_memory(c2, c8) USING HASH;
CREATE INDEX i29 ON positions_memory(c2, c9) USING HASH; CREATE INDEX i34 ON positions_memory(c3, c4) USING HASH;
CREATE INDEX i35 ON positions_memory(c3, c5) USING HASH; CREATE INDEX i36 ON positions_memory(c3, c6) USING HASH;
CREATE INDEX i37 ON positions_memory(c3, c7) USING HASH; CREATE INDEX i38 ON positions_memory(c3, c8) USING HASH;
CREATE INDEX i39 ON positions_memory(c3, c9) USING HASH; CREATE INDEX i45 ON positions_memory(c4, c5) USING HASH;
CREATE INDEX i46 ON positions_memory(c4, c6) USING HASH; CREATE INDEX i47 ON positions_memory(c4, c7) USING HASH;
CREATE INDEX i48 ON positions_memory(c4, c8) USING HASH; CREATE INDEX i49 ON positions_memory(c4, c9) USING HASH;
CREATE INDEX i56 ON positions_memory(c5, c6) USING HASH; CREATE INDEX i57 ON positions_memory(c5, c7) USING HASH;
CREATE INDEX i58 ON positions_memory(c5, c8) USING HASH; CREATE INDEX i59 ON positions_memory(c5, c9) USING HASH;
CREATE INDEX i67 ON positions_memory(c6, c7) USING HASH; CREATE INDEX i68 ON positions_memory(c6, c8) USING HASH;
CREATE INDEX i69 ON positions_memory(c6, c9) USING HASH; CREATE INDEX i78 ON positions_memory(c7, c8) USING HASH;
CREATE INDEX i79 ON positions_memory(c7, c9) USING HASH; CREATE INDEX i89 ON positions_memory(c8, c9) USING HASH;
CREATE INDEX i9 ON positions_memory(c9) USING HASH;

Maintenant, il s’agit de recréer les trois mêmes vues que nous avons créées pour le type de table MYISAM mais pour notre nouvelle table.

En premier lieu, la vue sur les rangées.

USE sudoku;

DROP VIEW IF EXISTS sudoku_memory_rows_view;
CREATE VIEW sudoku_memory_rows_view AS
SELECT
r1.c1 as r1c1, r1.c2 as r1c2, r1.c3 as r1c3, r1.c4 as r1c4, r1.c5 as r1c5, r1.c6 as r1c6, r1.c7 as r1c7, r1.c8 as r1c8, r1.c9 as r1c9, r2.c1 as r2c1,
r2.c2 as r2c2, r2.c3 as r2c3, r2.c4 as r2c4, r2.c5 as r2c5, r2.c6 as r2c6, r2.c7 as r2c7, r2.c8 as r2c8, r2.c9 as r2c9, r3.c1 as r3c1, r3.c2 as r3c2,
r3.c3 as r3c3, r3.c4 as r3c4, r3.c5 as r3c5, r3.c6 as r3c6, r3.c7 as r3c7, r3.c8 as r3c8, r3.c9 as r3c9, r4.c1 as r4c1, r4.c2 as r4c2, r4.c3 as r4c3,
r4.c4 as r4c4, r4.c5 as r4c5, r4.c6 as r4c6, r4.c7 as r4c7, r4.c8 as r4c8, r4.c9 as r4c9, r5.c1 as r5c1, r5.c2 as r5c2, r5.c3 as r5c3, r5.c4 as r5c4,
r5.c5 as r5c5, r5.c6 as r5c6, r5.c7 as r5c7, r5.c8 as r5c8, r5.c9 as r5c9, r6.c1 as r6c1, r6.c2 as r6c2, r6.c3 as r6c3, r6.c4 as r6c4, r6.c5 as r6c5,
r6.c6 as r6c6, r6.c7 as r6c7, r6.c8 as r6c8, r6.c9 as r6c9, r7.c1 as r7c1, r7.c2 as r7c2, r7.c3 as r7c3, r7.c4 as r7c4, r7.c5 as r7c5, r7.c6 as r7c6,
r7.c7 as r7c7, r7.c8 as r7c8, r7.c9 as r7c9, r8.c1 as r8c1, r8.c2 as r8c2, r8.c3 as r8c3, r8.c4 as r8c4, r8.c5 as r8c5, r8.c6 as r8c6, r8.c7 as r8c7,
r8.c8 as r8c8, r8.c9 as r8c9, r9.c1 as r9c1, r9.c2 as r9c2, r9.c3 as r9c3, r9.c4 as r9c4, r9.c5 as r9c5, r9.c6 as r9c6, r9.c7 as r9c7, r9.c8 as r9c8,
r9.c9 as r9c9

FROM
positions_memory r1, positions_memory r2, positions_memory r3,
positions_memory r4, positions_memory r5, positions_memory r6,
positions_memory r7, positions_memory r8, positions_memory r9

WHERE
-- Nombres uniques dans chaque colonne
(r1.c1 <> r2.c1) AND (r1.c1 <> r3.c1) AND (r1.c1 <> r4.c1) AND (r1.c1 <> r5.c1) AND (r1.c1 <> r6.c1) AND (r1.c1 <> r7.c1) AND (r1.c1 <> r8.c1) AND (r1.c1 <> r9.c1) AND (r1.c2 <> r2.c2) AND (r1.c2 <> r3.c2) AND (r1.c2 <> r4.c2) AND (r1.c2 <> r5.c2) AND (r1.c2 <> r6.c2) AND (r1.c2 <> r7.c2) AND (r1.c2 <> r8.c2) AND (r1.c2 <> r9.c2) AND
(r1.c3 <> r2.c3) AND (r1.c3 <> r3.c3) AND (r1.c3 <> r4.c3) AND (r1.c3 <> r5.c3) AND (r1.c3 <> r6.c3) AND (r1.c3 <> r7.c3) AND (r1.c3 <> r8.c3) AND (r1.c3 <> r9.c3) AND (r1.c4 <> r2.c4) AND (r1.c4 <> r3.c4) AND (r1.c4 <> r4.c4) AND (r1.c4 <> r5.c4) AND (r1.c4 <> r6.c4) AND (r1.c4 <> r7.c4) AND (r1.c4 <> r8.c4) AND (r1.c4 <> r9.c4) AND
(r1.c5 <> r2.c5) AND (r1.c5 <> r3.c5) AND (r1.c5 <> r4.c5) AND (r1.c5 <> r5.c5) AND (r1.c5 <> r6.c5) AND (r1.c5 <> r7.c5) AND (r1.c5 <> r8.c5) AND (r1.c5 <> r9.c5) AND (r1.c6 <> r2.c6) AND (r1.c6 <> r3.c6) AND (r1.c6 <> r4.c6) AND (r1.c6 <> r5.c6) AND (r1.c6 <> r6.c6) AND (r1.c6 <> r7.c6) AND (r1.c6 <> r8.c6) AND (r1.c6 <> r9.c6) AND
(r1.c7 <> r2.c7) AND (r1.c7 <> r3.c7) AND (r1.c7 <> r4.c7) AND (r1.c7 <> r5.c7) AND (r1.c7 <> r6.c7) AND (r1.c7 <> r7.c7) AND (r1.c7 <> r8.c7) AND (r1.c7 <> r9.c7) AND (r1.c8 <> r2.c8) AND (r1.c8 <> r3.c8) AND (r1.c8 <> r4.c8) AND (r1.c8 <> r5.c8) AND (r1.c8 <> r6.c8) AND (r1.c8 <> r7.c8) AND (r1.c8 <> r8.c8) AND (r1.c8 <> r9.c8) AND
(r1.c9 <> r2.c9) AND (r1.c9 <> r3.c9) AND (r1.c9 <> r4.c9) AND (r1.c9 <> r5.c9) AND (r1.c9 <> r6.c9) AND (r1.c9 <> r7.c9) AND (r1.c9 <> r8.c9) AND (r1.c9 <> r9.c9) AND (r2.c1 <> r3.c1) AND (r2.c1 <> r4.c1) AND (r2.c1 <> r5.c1) AND (r2.c1 <> r6.c1) AND (r2.c1 <> r7.c1) AND (r2.c1 <> r8.c1) AND (r2.c1 <> r9.c1) AND (r2.c2 <> r3.c2) AND
(r2.c2 <> r4.c2) AND (r2.c2 <> r5.c2) AND (r2.c2 <> r6.c2) AND (r2.c2 <> r7.c2) AND (r2.c2 <> r8.c2) AND (r2.c2 <> r9.c2) AND (r2.c3 <> r3.c3) AND (r2.c3 <> r4.c3) AND (r2.c3 <> r5.c3) AND (r2.c3 <> r6.c3) AND (r2.c3 <> r7.c3) AND (r2.c3 <> r8.c3) AND (r2.c3 <> r9.c3) AND (r2.c4 <> r3.c4) AND (r2.c4 <> r4.c4) AND (r2.c4 <> r5.c4) AND
(r2.c4 <> r6.c4) AND (r2.c4 <> r7.c4) AND (r2.c4 <> r8.c4) AND (r2.c4 <> r9.c4) AND (r2.c5 <> r3.c5) AND (r2.c5 <> r4.c5) AND (r2.c5 <> r5.c5) AND (r2.c5 <> r6.c5) AND (r2.c5 <> r7.c5) AND (r2.c5 <> r8.c5) AND (r2.c5 <> r9.c5) AND (r2.c6 <> r3.c6) AND (r2.c6 <> r4.c6) AND (r2.c6 <> r5.c6) AND (r2.c6 <> r6.c6) AND (r2.c6 <> r7.c6) AND
(r2.c6 <> r8.c6) AND (r2.c6 <> r9.c6) AND (r2.c7 <> r3.c7) AND (r2.c7 <> r4.c7) AND (r2.c7 <> r5.c7) AND (r2.c7 <> r6.c7) AND (r2.c7 <> r7.c7) AND (r2.c7 <> r8.c7) AND (r2.c7 <> r9.c7) AND (r2.c8 <> r3.c8) AND (r2.c8 <> r4.c8) AND (r2.c8 <> r5.c8) AND (r2.c8 <> r6.c8) AND (r2.c8 <> r7.c8) AND (r2.c8 <> r8.c8) AND (r2.c8 <> r9.c8) AND
(r2.c9 <> r3.c9) AND (r2.c9 <> r4.c9) AND (r2.c9 <> r5.c9) AND (r2.c9 <> r6.c9) AND (r2.c9 <> r7.c9) AND (r2.c9 <> r8.c9) AND (r2.c9 <> r9.c9) AND (r3.c1 <> r4.c1) AND (r3.c1 <> r5.c1) AND (r3.c1 <> r6.c1) AND (r3.c1 <> r7.c1) AND (r3.c1 <> r8.c1) AND (r3.c1 <> r9.c1) AND (r3.c2 <> r4.c2) AND (r3.c2 <> r5.c2) AND (r3.c2 <> r6.c2) AND
(r3.c2 <> r7.c2) AND (r3.c2 <> r8.c2) AND (r3.c2 <> r9.c2) AND (r3.c3 <> r4.c3) AND (r3.c3 <> r5.c3) AND (r3.c3 <> r6.c3) AND (r3.c3 <> r7.c3) AND (r3.c3 <> r8.c3) AND (r3.c3 <> r9.c3) AND (r3.c4 <> r4.c4) AND (r3.c4 <> r5.c4) AND (r3.c4 <> r6.c4) AND (r3.c4 <> r7.c4) AND (r3.c4 <> r8.c4) AND (r3.c4 <> r9.c4) AND (r3.c5 <> r4.c5) AND
(r3.c5 <> r5.c5) AND (r3.c5 <> r6.c5) AND (r3.c5 <> r7.c5) AND (r3.c5 <> r8.c5) AND (r3.c5 <> r9.c5) AND (r3.c6 <> r4.c6) AND (r3.c6 <> r5.c6) AND (r3.c6 <> r6.c6) AND (r3.c6 <> r7.c6) AND (r3.c6 <> r8.c6) AND (r3.c6 <> r9.c6) AND (r3.c7 <> r4.c7) AND (r3.c7 <> r5.c7) AND (r3.c7 <> r6.c7) AND (r3.c7 <> r7.c7) AND (r3.c7 <> r8.c7) AND
(r3.c7 <> r9.c7) AND (r3.c8 <> r4.c8) AND (r3.c8 <> r5.c8) AND (r3.c8 <> r6.c8) AND (r3.c8 <> r7.c8) AND (r3.c8 <> r8.c8) AND (r3.c8 <> r9.c8) AND (r3.c9 <> r4.c9) AND (r3.c9 <> r5.c9) AND (r3.c9 <> r6.c9) AND (r3.c9 <> r7.c9) AND (r3.c9 <> r8.c9) AND (r3.c9 <> r9.c9) AND (r4.c1 <> r5.c1) AND (r4.c1 <> r6.c1) AND (r4.c1 <> r7.c1) AND
(r4.c1 <> r8.c1) AND (r4.c1 <> r9.c1) AND (r4.c2 <> r5.c2) AND (r4.c2 <> r6.c2) AND (r4.c2 <> r7.c2) AND (r4.c2 <> r8.c2) AND (r4.c2 <> r9.c2) AND (r4.c3 <> r5.c3) AND (r4.c3 <> r6.c3) AND (r4.c3 <> r7.c3) AND (r4.c3 <> r8.c3) AND (r4.c3 <> r9.c3) AND (r4.c4 <> r5.c4) AND (r4.c4 <> r6.c4) AND (r4.c4 <> r7.c4) AND (r4.c4 <> r8.c4) AND
(r4.c4 <> r9.c4) AND (r4.c5 <> r5.c5) AND (r4.c5 <> r6.c5) AND (r4.c5 <> r7.c5) AND (r4.c5 <> r8.c5) AND (r4.c5 <> r9.c5) AND (r4.c6 <> r5.c6) AND (r4.c6 <> r6.c6) AND (r4.c6 <> r7.c6) AND (r4.c6 <> r8.c6) AND (r4.c6 <> r9.c6) AND (r4.c7 <> r5.c7) AND (r4.c7 <> r6.c7) AND (r4.c7 <> r7.c7) AND (r4.c7 <> r8.c7) AND (r4.c7 <> r9.c7) AND
(r4.c8 <> r5.c8) AND (r4.c8 <> r6.c8) AND (r4.c8 <> r7.c8) AND (r4.c8 <> r8.c8) AND (r4.c8 <> r9.c8) AND (r4.c9 <> r5.c9) AND (r4.c9 <> r6.c9) AND (r4.c9 <> r7.c9) AND (r4.c9 <> r8.c9) AND (r4.c9 <> r9.c9) AND (r5.c1 <> r6.c1) AND (r5.c1 <> r7.c1) AND (r5.c1 <> r8.c1) AND (r5.c1 <> r9.c1) AND (r5.c2 <> r6.c2) AND (r5.c2 <> r7.c2) AND
(r5.c2 <> r8.c2) AND (r5.c2 <> r9.c2) AND (r5.c3 <> r6.c3) AND (r5.c3 <> r7.c3) AND (r5.c3 <> r8.c3) AND (r5.c3 <> r9.c3) AND (r5.c4 <> r6.c4) AND (r5.c4 <> r7.c4) AND (r5.c4 <> r8.c4) AND (r5.c4 <> r9.c4) AND (r5.c5 <> r6.c5) AND (r5.c5 <> r7.c5) AND (r5.c5 <> r8.c5) AND (r5.c5 <> r9.c5) AND (r5.c6 <> r6.c6) AND (r5.c6 <> r7.c6) AND
(r5.c6 <> r8.c6) AND (r5.c6 <> r9.c6) AND (r5.c7 <> r6.c7) AND (r5.c7 <> r7.c7) AND (r5.c7 <> r8.c7) AND (r5.c7 <> r9.c7) AND (r5.c8 <> r6.c8) AND (r5.c8 <> r7.c8) AND (r5.c8 <> r8.c8) AND (r5.c8 <> r9.c8) AND (r5.c9 <> r6.c9) AND (r5.c9 <> r7.c9) AND (r5.c9 <> r8.c9) AND (r5.c9 <> r9.c9) AND (r6.c1 <> r7.c1) AND (r6.c1 <> r8.c1) AND
(r6.c1 <> r9.c1) AND (r6.c2 <> r7.c2) AND (r6.c2 <> r8.c2) AND (r6.c2 <> r9.c2) AND (r6.c3 <> r7.c3) AND (r6.c3 <> r8.c3) AND (r6.c3 <> r9.c3) AND (r6.c4 <> r7.c4) AND (r6.c4 <> r8.c4) AND (r6.c4 <> r9.c4) AND (r6.c5 <> r7.c5) AND (r6.c5 <> r8.c5) AND (r6.c5 <> r9.c5) AND (r6.c6 <> r7.c6) AND (r6.c6 <> r8.c6) AND (r6.c6 <> r9.c6) AND
(r6.c7 <> r7.c7) AND (r6.c7 <> r8.c7) AND (r6.c7 <> r9.c7) AND (r6.c8 <> r7.c8) AND (r6.c8 <> r8.c8) AND (r6.c8 <> r9.c8) AND (r6.c9 <> r7.c9) AND (r6.c9 <> r8.c9) AND (r6.c9 <> r9.c9) AND (r7.c1 <> r8.c1) AND (r7.c1 <> r9.c1) AND (r7.c2 <> r8.c2) AND (r7.c2 <> r9.c2) AND (r7.c3 <> r8.c3) AND (r7.c3 <> r9.c3) AND (r7.c4 <> r8.c4) AND
(r7.c4 <> r9.c4) AND (r7.c5 <> r8.c5) AND (r7.c5 <> r9.c5) AND (r7.c6 <> r8.c6) AND (r7.c6 <> r9.c6) AND (r7.c7 <> r8.c7) AND (r7.c7 <> r9.c7) AND (r7.c8 <> r8.c8) AND (r7.c8 <> r9.c8) AND (r7.c9 <> r8.c9) AND (r7.c9 <> r9.c9) AND (r8.c1 <> r9.c1) AND (r8.c2 <> r9.c2) AND (r8.c3 <> r9.c3) AND (r8.c4 <> r9.c4) AND (r8.c5 <> r9.c5) AND
(r8.c6 <> r9.c6) AND (r8.c7 <> r9.c7) AND (r8.c8 <> r9.c8) AND (r8.c9 <> r9.c9) AND
-- Nombres uniques dans chaque maison de 3x3
(r1.c1 <> r2.c2) AND (r1.c1 <> r2.c3) AND (r1.c1 <> r3.c2) AND (r1.c1 <> r3.c3) AND (r1.c2 <> r2.c1) AND (r1.c2 <> r2.c3) AND (r1.c2 <> r3.c1) AND (r1.c2 <> r3.c3) AND (r1.c3 <> r2.c1) AND (r1.c3 <> r2.c2) AND (r1.c3 <> r3.c1) AND (r1.c3 <> r3.c2) AND (r1.c4 <> r2.c5) AND (r1.c4 <> r2.c6) AND (r1.c4 <> r3.c5) AND (r1.c4 <> r3.c6) AND
(r1.c5 <> r2.c4) AND (r1.c5 <> r2.c6) AND (r1.c5 <> r3.c4) AND (r1.c5 <> r3.c6) AND (r1.c6 <> r2.c4) AND (r1.c6 <> r2.c5) AND (r1.c6 <> r3.c4) AND (r1.c6 <> r3.c5) AND (r1.c7 <> r2.c8) AND (r1.c7 <> r2.c9) AND (r1.c7 <> r3.c8) AND (r1.c7 <> r3.c9) AND (r1.c8 <> r2.c7) AND (r1.c8 <> r2.c9) AND (r1.c8 <> r3.c7) AND (r1.c8 <> r3.c9) AND
(r1.c9 <> r2.c7) AND (r1.c9 <> r2.c8) AND (r1.c9 <> r3.c7) AND (r1.c9 <> r3.c8) AND (r2.c1 <> r3.c2) AND (r2.c1 <> r3.c3) AND (r2.c2 <> r3.c1) AND (r2.c2 <> r3.c3) AND (r2.c3 <> r3.c1) AND (r2.c3 <> r3.c2) AND (r2.c4 <> r3.c5) AND (r2.c4 <> r3.c6) AND (r2.c5 <> r3.c4) AND (r2.c5 <> r3.c6) AND (r2.c6 <> r3.c4) AND (r2.c6 <> r3.c5) AND
(r2.c7 <> r3.c8) AND (r2.c7 <> r3.c9) AND (r2.c8 <> r3.c7) AND (r2.c8 <> r3.c9) AND (r2.c9 <> r3.c7) AND (r2.c9 <> r3.c8) AND (r4.c1 <> r5.c2) AND (r4.c1 <> r5.c3) AND (r4.c1 <> r6.c2) AND (r4.c1 <> r6.c3) AND (r4.c2 <> r5.c1) AND (r4.c2 <> r5.c3) AND (r4.c2 <> r6.c1) AND (r4.c2 <> r6.c3) AND (r4.c3 <> r5.c1) AND (r4.c3 <> r5.c2) AND
(r4.c3 <> r6.c1) AND (r4.c3 <> r6.c2) AND (r4.c4 <> r5.c5) AND (r4.c4 <> r5.c6) AND (r4.c4 <> r6.c5) AND (r4.c4 <> r6.c6) AND (r4.c5 <> r5.c4) AND (r4.c5 <> r5.c6) AND (r4.c5 <> r6.c4) AND (r4.c5 <> r6.c6) AND (r4.c6 <> r5.c4) AND (r4.c6 <> r5.c5) AND (r4.c6 <> r6.c4) AND (r4.c6 <> r6.c5) AND (r4.c7 <> r5.c8) AND (r4.c7 <> r5.c9) AND
(r4.c7 <> r6.c8) AND (r4.c7 <> r6.c9) AND (r4.c8 <> r5.c7) AND (r4.c8 <> r5.c9) AND (r4.c8 <> r6.c7) AND (r4.c8 <> r6.c9) AND (r4.c9 <> r5.c7) AND (r4.c9 <> r5.c8) AND (r4.c9 <> r6.c7) AND (r4.c9 <> r6.c8) AND (r5.c1 <> r6.c2) AND (r5.c1 <> r6.c3) AND (r5.c2 <> r6.c1) AND (r5.c2 <> r6.c3) AND (r5.c3 <> r6.c1) AND (r5.c3 <> r6.c2) AND
(r5.c4 <> r6.c5) AND (r5.c4 <> r6.c6) AND (r5.c5 <> r6.c4) AND (r5.c5 <> r6.c6) AND (r5.c6 <> r6.c4) AND (r5.c6 <> r6.c5) AND (r5.c7 <> r6.c8) AND (r5.c7 <> r6.c9) AND (r5.c8 <> r6.c7) AND (r5.c8 <> r6.c9) AND (r5.c9 <> r6.c7) AND (r5.c9 <> r6.c8) AND (r7.c1 <> r8.c2) AND (r7.c1 <> r8.c3) AND (r7.c1 <> r9.c2) AND (r7.c1 <> r9.c3) AND
(r7.c2 <> r8.c1) AND (r7.c2 <> r8.c3) AND (r7.c2 <> r9.c1) AND (r7.c2 <> r9.c3) AND (r7.c3 <> r8.c1) AND (r7.c3 <> r8.c2) AND (r7.c3 <> r9.c1) AND (r7.c3 <> r9.c2) AND (r7.c4 <> r8.c5) AND (r7.c4 <> r8.c6) AND (r7.c4 <> r9.c5) AND (r7.c4 <> r9.c6) AND (r7.c5 <> r8.c4) AND (r7.c5 <> r8.c6) AND (r7.c5 <> r9.c4) AND (r7.c5 <> r9.c6) AND
(r7.c6 <> r8.c4) AND (r7.c6 <> r8.c5) AND (r7.c6 <> r9.c4) AND (r7.c6 <> r9.c5) AND (r7.c7 <> r8.c8) AND (r7.c7 <> r8.c9) AND (r7.c7 <> r9.c8) AND (r7.c7 <> r9.c9) AND (r7.c8 <> r8.c7) AND (r7.c8 <> r8.c9) AND (r7.c8 <> r9.c7) AND (r7.c8 <> r9.c9) AND (r7.c9 <> r8.c7) AND (r7.c9 <> r8.c8) AND (r7.c9 <> r9.c7) AND (r7.c9 <> r9.c8) AND
(r8.c1 <> r9.c2) AND (r8.c1 <> r9.c3) AND (r8.c2 <> r9.c1) AND (r8.c2 <> r9.c3) AND (r8.c3 <> r9.c1) AND (r8.c3 <> r9.c2) AND (r8.c4 <> r9.c5) AND (r8.c4 <> r9.c6) AND (r8.c5 <> r9.c4) AND (r8.c5 <> r9.c6) AND (r8.c6 <> r9.c4) AND (r8.c6 <> r9.c5) AND (r8.c7 <> r9.c8) AND (r8.c7 <> r9.c9) AND (r8.c8 <> r9.c7) AND (r8.c8 <> r9.c9) AND
(r8.c9 <> r9.c7) AND (r8.c9 <> r9.c8);

En second lieu, la vue sur les colonnes.

USE sudoku;

DROP VIEW IF EXISTS sudoku_memory_columns_view;
CREATE VIEW sudoku_memory_columns_view AS
SELECT
col1.c1 as r1c1, col1.c2 as r2c1, col1.c3 as r3c1, col1.c4 as r4c1, col1.c5 as r5c1,col1.c6 as r6c1, col1.c7 as r7c1, col1.c8 as r8c1, col1.c9 as r9c1, col2.c1 as r1c2,
col2.c2 as r2c2, col2.c3 as r3c2, col2.c4 as r4c2, col2.c5 as r5c2, col2.c6 as r6c2,col2.c7 as r7c2, col2.c8 as r8c2, col2.c9 as r9c2, col3.c1 as r1c3, col3.c2 as r2c3,
col3.c3 as r3c3, col3.c4 as r4c3, col3.c5 as r5c3, col3.c6 as r6c3, col3.c7 as r7c3,col3.c8 as r8c3, col3.c9 as r9c3, col4.c1 as r1c4, col4.c2 as r2c4, col4.c3 as r3c4,
col4.c4 as r4c4, col4.c5 as r5c4, col4.c6 as r6c4, col4.c7 as r7c4, col4.c8 as r8c4,col4.c9 as r9c4, col5.c1 as r1c5, col5.c2 as r2c5, col5.c3 as r3c5, col5.c4 as r4c5,
col5.c5 as r5c5, col5.c6 as r6c5, col5.c7 as r7c5, col5.c8 as r8c5, col5.c9 as r9c5,col6.c1 as r1c6, col6.c2 as r2c6, col6.c3 as r3c6, col6.c4 as r4c6, col6.c5 as r5c6,
col6.c6 as r6c6, col6.c7 as r7c6, col6.c8 as r8c6, col6.c9 as r9c6, col7.c1 as r1c7,col7.c2 as r2c7, col7.c3 as r3c7, col7.c4 as r4c7, col7.c5 as r5c7, col7.c6 as r6c7,
col7.c7 as r7c7, col7.c8 as r8c7, col7.c9 as r9c7, col8.c1 as r1c8, col8.c2 as r2c8,col8.c3 as r3c8, col8.c4 as r4c8, col8.c5 as r5c8, col8.c6 as r6c8, col8.c7 as r7c8,
col8.c8 as r8c8, col8.c9 as r9c8, col9.c1 as r1c9, col9.c2 as r2c9, col9.c3 as r3c9,col9.c4 as r4c9, col9.c5 as r5c9, col9.c6 as r6c9, col9.c7 as r7c9, col9.c8 as r8c9,
col9.c9 as r9c9
FROM
positions_memory col1, positions_memory col2, positions_memory col3, positions_memory col4,
positions_memory col5, positions_memory col6, positions_memory col7, positions_memory col8, positions_memory col9
WHERE
-- Nombres uniques dans chaque rangee
(col1.c1 <> col2.c1) AND (col1.c1 <> col3.c1) AND (col1.c1 <> col4.c1) AND (col1.c1 <> col5.c1) AND (col1.c1 <> col6.c1) AND (col1.c1 <> col7.c1) AND (col1.c1 <> col8.c1) AND (col1.c1 <> col9.c1) AND (col1.c2 <> col2.c2) AND (col1.c2 <> col3.c2) AND (col1.c2 <> col4.c2) AND (col1.c2 <> col5.c2) AND (col1.c2 <> col6.c2) AND (col1.c2 <> col7.c2) AND (col1.c2 <> col8.c2) AND (col1.c2 <> col9.c2) AND (col1.c3 <> col2.c3) AND (col1.c3 <> col3.c3) AND (col1.c3 <> col4.c3) AND (col1.c3 <> col5.c3) AND (col1.c3 <> col6.c3) AND (col1.c3 <> col7.c3) AND (col1.c3 <> col8.c3) AND (col1.c3 <> col9.c3) AND (col1.c4 <> col2.c4) AND (col1.c4 <> col3.c4) AND (col1.c4 <> col4.c4) AND (col1.c4 <> col5.c4) AND (col1.c4 <> col6.c4) AND (col1.c4 <> col7.c4) AND (col1.c4 <> col8.c4) AND (col1.c4 <> col9.c4) AND
(col1.c5 <> col2.c5) AND (col1.c5 <> col3.c5) AND (col1.c5 <> col4.c5) AND (col1.c5 <> col5.c5) AND (col1.c5 <> col6.c5) AND (col1.c5 <> col7.c5) AND (col1.c5 <> col8.c5) AND (col1.c5 <> col9.c5) AND (col1.c6 <> col2.c6) AND (col1.c6 <> col3.c6) AND (col1.c6 <> col4.c6) AND (col1.c6 <> col5.c6) AND (col1.c6 <> col6.c6) AND (col1.c6 <> col7.c6) AND (col1.c6 <> col8.c6) AND (col1.c6 <> col9.c6) AND (col1.c7 <> col2.c7) AND (col1.c7 <> col3.c7) AND (col1.c7 <> col4.c7) AND (col1.c7 <> col5.c7) AND (col1.c7 <> col6.c7) AND (col1.c7 <> col7.c7) AND (col1.c7 <> col8.c7) AND (col1.c7 <> col9.c7) AND (col1.c8 <> col2.c8) AND (col1.c8 <> col3.c8) AND (col1.c8 <> col4.c8) AND (col1.c8 <> col5.c8) AND (col1.c8 <> col6.c8) AND (col1.c8 <> col7.c8) AND (col1.c8 <> col8.c8) AND (col1.c8 <> col9.c8) AND
(col1.c9 <> col2.c9) AND (col1.c9 <> col3.c9) AND (col1.c9 <> col4.c9) AND (col1.c9 <> col5.c9) AND (col1.c9 <> col6.c9) AND (col1.c9 <> col7.c9) AND (col1.c9 <> col8.c9) AND (col1.c9 <> col9.c9) AND (col2.c1 <> col3.c1) AND (col2.c1 <> col4.c1) AND (col2.c1 <> col5.c1) AND (col2.c1 <> col6.c1) AND (col2.c1 <> col7.c1) AND (col2.c1 <> col8.c1) AND (col2.c1 <> col9.c1) AND (col2.c2 <> col3.c2) AND (col2.c2 <> col4.c2) AND (col2.c2 <> col5.c2) AND (col2.c2 <> col6.c2) AND (col2.c2 <> col7.c2) AND (col2.c2 <> col8.c2) AND (col2.c2 <> col9.c2) AND (col2.c3 <> col3.c3) AND (col2.c3 <> col4.c3) AND (col2.c3 <> col5.c3) AND (col2.c3 <> col6.c3) AND (col2.c3 <> col7.c3) AND (col2.c3 <> col8.c3) AND (col2.c3 <> col9.c3) AND (col2.c4 <> col3.c4) AND (col2.c4 <> col4.c4) AND (col2.c4 <> col5.c4) AND
(col2.c4 <> col6.c4) AND (col2.c4 <> col7.c4) AND (col2.c4 <> col8.c4) AND (col2.c4 <> col9.c4) AND (col2.c5 <> col3.c5) AND (col2.c5 <> col4.c5) AND (col2.c5 <> col5.c5) AND (col2.c5 <> col6.c5) AND (col2.c5 <> col7.c5) AND (col2.c5 <> col8.c5) AND (col2.c5 <> col9.c5) AND (col2.c6 <> col3.c6) AND (col2.c6 <> col4.c6) AND (col2.c6 <> col5.c6) AND (col2.c6 <> col6.c6) AND (col2.c6 <> col7.c6) AND (col2.c6 <> col8.c6) AND (col2.c6 <> col9.c6) AND (col2.c7 <> col3.c7) AND (col2.c7 <> col4.c7) AND (col2.c7 <> col5.c7) AND (col2.c7 <> col6.c7) AND (col2.c7 <> col7.c7) AND (col2.c7 <> col8.c7) AND (col2.c7 <> col9.c7) AND (col2.c8 <> col3.c8) AND (col2.c8 <> col4.c8) AND (col2.c8 <> col5.c8) AND (col2.c8 <> col6.c8) AND (col2.c8 <> col7.c8) AND (col2.c8 <> col8.c8) AND (col2.c8 <> col9.c8) AND
(col2.c9 <> col3.c9) AND (col2.c9 <> col4.c9) AND (col2.c9 <> col5.c9) AND (col2.c9 <> col6.c9) AND (col2.c9 <> col7.c9) AND (col2.c9 <> col8.c9) AND (col2.c9 <> col9.c9) AND (col3.c1 <> col4.c1) AND (col3.c1 <> col5.c1) AND (col3.c1 <> col6.c1) AND (col3.c1 <> col7.c1) AND (col3.c1 <> col8.c1) AND (col3.c1 <> col9.c1) AND (col3.c2 <> col4.c2) AND (col3.c2 <> col5.c2) AND (col3.c2 <> col6.c2) AND (col3.c2 <> col7.c2) AND (col3.c2 <> col8.c2) AND (col3.c2 <> col9.c2) AND (col3.c3 <> col4.c3) AND (col3.c3 <> col5.c3) AND (col3.c3 <> col6.c3) AND (col3.c3 <> col7.c3) AND (col3.c3 <> col8.c3) AND (col3.c3 <> col9.c3) AND (col3.c4 <> col4.c4) AND (col3.c4 <> col5.c4) AND (col3.c4 <> col6.c4) AND (col3.c4 <> col7.c4) AND (col3.c4 <> col8.c4) AND (col3.c4 <> col9.c4) AND (col3.c5 <> col4.c5) AND
(col3.c5 <> col5.c5) AND (col3.c5 <> col6.c5) AND (col3.c5 <> col7.c5) AND (col3.c5 <> col8.c5) AND (col3.c5 <> col9.c5) AND (col3.c6 <> col4.c6) AND (col3.c6 <> col5.c6) AND (col3.c6 <> col6.c6) AND (col3.c6 <> col7.c6) AND (col3.c6 <> col8.c6) AND (col3.c6 <> col9.c6) AND (col3.c7 <> col4.c7) AND (col3.c7 <> col5.c7) AND (col3.c7 <> col6.c7) AND (col3.c7 <> col7.c7) AND (col3.c7 <> col8.c7) AND (col3.c7 <> col9.c7) AND (col3.c8 <> col4.c8) AND (col3.c8 <> col5.c8) AND (col3.c8 <> col6.c8) AND (col3.c8 <> col7.c8) AND (col3.c8 <> col8.c8) AND (col3.c8 <> col9.c8) AND (col3.c9 <> col4.c9) AND (col3.c9 <> col5.c9) AND (col3.c9 <> col6.c9) AND (col3.c9 <> col7.c9) AND (col3.c9 <> col8.c9) AND (col3.c9 <> col9.c9) AND (col4.c1 <> col5.c1) AND (col4.c1 <> col6.c1) AND (col4.c1 <> col7.c1) AND
(col4.c1 <> col8.c1) AND (col4.c1 <> col9.c1) AND (col4.c2 <> col5.c2) AND (col4.c2 <> col6.c2) AND (col4.c2 <> col7.c2) AND (col4.c2 <> col8.c2) AND (col4.c2 <> col9.c2) AND (col4.c3 <> col5.c3) AND (col4.c3 <> col6.c3) AND (col4.c3 <> col7.c3) AND (col4.c3 <> col8.c3) AND (col4.c3 <> col9.c3) AND (col4.c4 <> col5.c4) AND (col4.c4 <> col6.c4) AND (col4.c4 <> col7.c4) AND (col4.c4 <> col8.c4) AND (col4.c4 <> col9.c4) AND (col4.c5 <> col5.c5) AND (col4.c5 <> col6.c5) AND (col4.c5 <> col7.c5) AND (col4.c5 <> col8.c5) AND (col4.c5 <> col9.c5) AND (col4.c6 <> col5.c6) AND (col4.c6 <> col6.c6) AND (col4.c6 <> col7.c6) AND (col4.c6 <> col8.c6) AND (col4.c6 <> col9.c6) AND (col4.c7 <> col5.c7) AND (col4.c7 <> col6.c7) AND (col4.c7 <> col7.c7) AND (col4.c7 <> col8.c7) AND (col4.c7 <> col9.c7) AND
(col4.c8 <> col5.c8) AND (col4.c8 <> col6.c8) AND (col4.c8 <> col7.c8) AND (col4.c8 <> col8.c8) AND (col4.c8 <> col9.c8) AND (col4.c9 <> col5.c9) AND (col4.c9 <> col6.c9) AND (col4.c9 <> col7.c9) AND (col4.c9 <> col8.c9) AND (col4.c9 <> col9.c9) AND (col5.c1 <> col6.c1) AND (col5.c1 <> col7.c1) AND (col5.c1 <> col8.c1) AND (col5.c1 <> col9.c1) AND (col5.c2 <> col6.c2) AND (col5.c2 <> col7.c2) AND (col5.c2 <> col8.c2) AND (col5.c2 <> col9.c2) AND (col5.c3 <> col6.c3) AND (col5.c3 <> col7.c3) AND (col5.c3 <> col8.c3) AND (col5.c3 <> col9.c3) AND (col5.c4 <> col6.c4) AND (col5.c4 <> col7.c4) AND (col5.c4 <> col8.c4) AND (col5.c4 <> col9.c4) AND (col5.c5 <> col6.c5) AND (col5.c5 <> col7.c5) AND (col5.c5 <> col8.c5) AND (col5.c5 <> col9.c5) AND (col5.c6 <> col6.c6) AND (col5.c6 <> col7.c6) AND
(col5.c6 <> col8.c6) AND (col5.c6 <> col9.c6) AND (col5.c7 <> col6.c7) AND (col5.c7 <> col7.c7) AND (col5.c7 <> col8.c7) AND (col5.c7 <> col9.c7) AND (col5.c8 <> col6.c8) AND (col5.c8 <> col7.c8) AND (col5.c8 <> col8.c8) AND (col5.c8 <> col9.c8) AND (col5.c9 <> col6.c9) AND (col5.c9 <> col7.c9) AND (col5.c9 <> col8.c9) AND (col5.c9 <> col9.c9) AND (col6.c1 <> col7.c1) AND (col6.c1 <> col8.c1) AND (col6.c1 <> col9.c1) AND (col6.c2 <> col7.c2) AND (col6.c2 <> col8.c2) AND (col6.c2 <> col9.c2) AND (col6.c3 <> col7.c3) AND (col6.c3 <> col8.c3) AND (col6.c3 <> col9.c3) AND (col6.c4 <> col7.c4) AND (col6.c4 <> col8.c4) AND (col6.c4 <> col9.c4) AND (col6.c5 <> col7.c5) AND (col6.c5 <> col8.c5) AND (col6.c5 <> col9.c5) AND (col6.c6 <> col7.c6) AND (col6.c6 <> col8.c6) AND (col6.c6 <> col9.c6) AND
(col6.c7 <> col7.c7) AND (col6.c7 <> col8.c7) AND (col6.c7 <> col9.c7) AND (col6.c8 <> col7.c8) AND (col6.c8 <> col8.c8) AND (col6.c8 <> col9.c8) AND (col6.c9 <> col7.c9) AND (col6.c9 <> col8.c9) AND (col6.c9 <> col9.c9) AND (col7.c1 <> col8.c1) AND (col7.c1 <> col9.c1) AND (col7.c2 <> col8.c2) AND (col7.c2 <> col9.c2) AND (col7.c3 <> col8.c3) AND (col7.c3 <> col9.c3) AND (col7.c4 <> col8.c4) AND (col7.c4 <> col9.c4) AND (col7.c5 <> col8.c5) AND (col7.c5 <> col9.c5) AND (col7.c6 <> col8.c6) AND (col7.c6 <> col9.c6) AND (col7.c7 <> col8.c7) AND (col7.c7 <> col9.c7) AND (col7.c8 <> col8.c8) AND (col7.c8 <> col9.c8) AND (col7.c9 <> col8.c9) AND (col7.c9 <> col9.c9) AND (col8.c1 <> col9.c1) AND (col8.c2 <> col9.c2) AND (col8.c3 <> col9.c3) AND (col8.c4 <> col9.c4) AND (col8.c5 <> col9.c5) AND
(col8.c6 <> col9.c6) AND (col8.c7 <> col9.c7) AND (col8.c8 <> col9.c8) AND (col8.c9 <> col9.c9) AND
-- Nombres uniques dans chaque maison de 3x3
(col1.c1 <> col1.c2) AND (col1.c1 <> col1.c3) AND (col1.c1 <> col2.c2) AND (col1.c1 <> col2.c3) AND (col1.c1 <> col3.c2) AND (col1.c1 <> col3.c3) AND (col1.c2 <> col1.c3) AND (col1.c2 <> col2.c1) AND (col1.c2 <> col2.c3) AND (col1.c2 <> col3.c1) AND (col1.c2 <> col3.c3) AND (col1.c3 <> col2.c1) AND (col1.c3 <> col2.c2) AND (col1.c3 <> col3.c1) AND (col1.c3 <> col3.c2) AND (col1.c4 <> col1.c5) AND (col1.c4 <> col1.c6) AND (col1.c4 <> col2.c5) AND (col1.c4 <> col2.c6) AND (col1.c4 <> col3.c5) AND (col1.c4 <> col3.c6) AND (col1.c5 <> col1.c6) AND (col1.c5 <> col2.c4) AND (col1.c5 <> col2.c6) AND (col1.c5 <> col3.c4) AND (col1.c5 <> col3.c6) AND (col1.c6 <> col2.c4) AND (col1.c6 <> col2.c5) AND (col1.c6 <> col3.c4) AND (col1.c6 <> col3.c5) AND (col1.c7 <> col1.c8) AND (col1.c7 <> col1.c9) AND
(col1.c7 <> col2.c8) AND (col1.c7 <> col2.c9) AND (col1.c7 <> col3.c8) AND (col1.c7 <> col3.c9) AND (col1.c8 <> col1.c9) AND (col1.c8 <> col2.c7) AND (col1.c8 <> col2.c9) AND (col1.c8 <> col3.c7) AND (col1.c8 <> col3.c9) AND (col1.c9 <> col2.c7) AND (col1.c9 <> col2.c8) AND (col1.c9 <> col3.c7) AND (col1.c9 <> col3.c8) AND (col2.c1 <> col2.c2) AND (col2.c1 <> col2.c3) AND (col2.c1 <> col3.c2) AND (col2.c1 <> col3.c3) AND (col2.c2 <> col2.c3) AND (col2.c2 <> col3.c1) AND (col2.c2 <> col3.c3) AND (col2.c3 <> col3.c1) AND (col2.c3 <> col3.c2) AND (col2.c4 <> col2.c5) AND (col2.c4 <> col2.c6) AND (col2.c4 <> col3.c5) AND (col2.c4 <> col3.c6) AND (col2.c5 <> col2.c6) AND (col2.c5 <> col3.c4) AND (col2.c5 <> col3.c6) AND (col2.c6 <> col3.c4) AND (col2.c6 <> col3.c5) AND (col2.c7 <> col2.c8) AND
(col2.c7 <> col2.c9) AND (col2.c7 <> col3.c8) AND (col2.c7 <> col3.c9) AND (col2.c8 <> col2.c9) AND (col2.c8 <> col3.c7) AND (col2.c8 <> col3.c9) AND (col2.c9 <> col3.c7) AND (col2.c9 <> col3.c8) AND (col3.c1 <> col3.c2) AND (col3.c1 <> col3.c3) AND (col3.c2 <> col3.c3) AND (col3.c4 <> col3.c5) AND (col3.c4 <> col3.c6) AND (col3.c5 <> col3.c6) AND (col3.c7 <> col3.c8) AND (col3.c7 <> col3.c9) AND (col3.c8 <> col3.c9) AND (col4.c1 <> col4.c2) AND (col4.c1 <> col4.c3) AND (col4.c1 <> col5.c2) AND (col4.c1 <> col5.c3) AND (col4.c1 <> col6.c2) AND (col4.c1 <> col6.c3) AND (col4.c2 <> col4.c3) AND (col4.c2 <> col5.c1) AND (col4.c2 <> col5.c3) AND (col4.c2 <> col6.c1) AND (col4.c2 <> col6.c3) AND (col4.c3 <> col5.c1) AND (col4.c3 <> col5.c2) AND (col4.c3 <> col6.c1) AND (col4.c3 <> col6.c2) AND
(col4.c4 <> col4.c5) AND (col4.c4 <> col4.c6) AND (col4.c4 <> col5.c5) AND (col4.c4 <> col5.c6) AND (col4.c4 <> col6.c5) AND (col4.c4 <> col6.c6) AND (col4.c5 <> col4.c6) AND (col4.c5 <> col5.c4) AND (col4.c5 <> col5.c6) AND (col4.c5 <> col6.c4) AND (col4.c5 <> col6.c6) AND (col4.c6 <> col5.c4) AND (col4.c6 <> col5.c5) AND (col4.c6 <> col6.c4) AND (col4.c6 <> col6.c5) AND (col4.c7 <> col4.c8) AND (col4.c7 <> col4.c9) AND (col4.c7 <> col5.c8) AND (col4.c7 <> col5.c9) AND (col4.c7 <> col6.c8) AND (col4.c7 <> col6.c9) AND (col4.c8 <> col4.c9) AND (col4.c8 <> col5.c7) AND (col4.c8 <> col5.c9) AND (col4.c8 <> col6.c7) AND (col4.c8 <> col6.c9) AND (col4.c9 <> col5.c7) AND (col4.c9 <> col5.c8) AND (col4.c9 <> col6.c7) AND (col4.c9 <> col6.c8) AND (col5.c1 <> col5.c2) AND (col5.c1 <> col5.c3) AND
(col5.c1 <> col6.c2) AND (col5.c1 <> col6.c3) AND (col5.c2 <> col5.c3) AND (col5.c2 <> col6.c1) AND (col5.c2 <> col6.c3) AND (col5.c3 <> col6.c1) AND (col5.c3 <> col6.c2) AND (col5.c4 <> col5.c5) AND (col5.c4 <> col5.c6) AND (col5.c4 <> col6.c5) AND (col5.c4 <> col6.c6) AND (col5.c5 <> col5.c6) AND (col5.c5 <> col6.c4) AND (col5.c5 <> col6.c6) AND (col5.c6 <> col6.c4) AND (col5.c6 <> col6.c5) AND (col5.c7 <> col5.c8) AND (col5.c7 <> col5.c9) AND (col5.c7 <> col6.c8) AND (col5.c7 <> col6.c9) AND (col5.c8 <> col5.c9) AND (col5.c8 <> col6.c7) AND (col5.c8 <> col6.c9) AND (col5.c9 <> col6.c7) AND (col5.c9 <> col6.c8) AND (col6.c1 <> col6.c2) AND (col6.c1 <> col6.c3) AND (col6.c2 <> col6.c3) AND (col6.c4 <> col6.c5) AND (col6.c4 <> col6.c6) AND (col6.c5 <> col6.c6) AND (col6.c7 <> col6.c8) AND
(col6.c7 <> col6.c9) AND (col6.c8 <> col6.c9) AND (col7.c1 <> col7.c2) AND (col7.c1 <> col7.c3) AND (col7.c1 <> col8.c2) AND (col7.c1 <> col8.c3) AND (col7.c1 <> col9.c2) AND (col7.c1 <> col9.c3) AND (col7.c2 <> col7.c3) AND (col7.c2 <> col8.c1) AND (col7.c2 <> col8.c3) AND (col7.c2 <> col9.c1) AND (col7.c2 <> col9.c3) AND (col7.c3 <> col8.c1) AND (col7.c3 <> col8.c2) AND (col7.c3 <> col9.c1) AND (col7.c3 <> col9.c2) AND (col7.c4 <> col7.c5) AND (col7.c4 <> col7.c6) AND (col7.c4 <> col8.c5) AND (col7.c4 <> col8.c6) AND (col7.c4 <> col9.c5) AND (col7.c4 <> col9.c6) AND (col7.c5 <> col7.c6) AND (col7.c5 <> col8.c4) AND (col7.c5 <> col8.c6) AND (col7.c5 <> col9.c4) AND (col7.c5 <> col9.c6) AND (col7.c6 <> col8.c4) AND (col7.c6 <> col8.c5) AND (col7.c6 <> col9.c4) AND (col7.c6 <> col9.c5) AND
(col7.c7 <> col7.c8) AND (col7.c7 <> col7.c9) AND (col7.c7 <> col8.c8) AND (col7.c7 <> col8.c9) AND (col7.c7 <> col9.c8) AND (col7.c7 <> col9.c9) AND (col7.c8 <> col7.c9) AND (col7.c8 <> col8.c7) AND (col7.c8 <> col8.c9) AND (col7.c8 <> col9.c7) AND (col7.c8 <> col9.c9) AND (col7.c9 <> col8.c7) AND (col7.c9 <> col8.c8) AND (col7.c9 <> col9.c7) AND (col7.c9 <> col9.c8) AND (col8.c1 <> col8.c2) AND (col8.c1 <> col8.c3) AND (col8.c1 <> col9.c2) AND (col8.c1 <> col9.c3) AND (col8.c2 <> col8.c3) AND (col8.c2 <> col9.c1) AND (col8.c2 <> col9.c3) AND (col8.c3 <> col9.c1) AND (col8.c3 <> col9.c2) AND (col8.c4 <> col8.c5) AND (col8.c4 <> col8.c6) AND (col8.c4 <> col9.c5) AND (col8.c4 <> col9.c6) AND (col8.c5 <> col8.c6) AND (col8.c5 <> col9.c4) AND (col8.c5 <> col9.c6) AND (col8.c6 <> col9.c4) AND
(col8.c6 <> col9.c5) AND (col8.c7 <> col8.c8) AND (col8.c7 <> col8.c9) AND (col8.c7 <> col9.c8) AND (col8.c7 <> col9.c9) AND (col8.c8 <> col8.c9) AND (col8.c8 <> col9.c7) AND (col8.c8 <> col9.c9) AND (col8.c9 <> col9.c7) AND (col8.c9 <> col9.c8) AND (col9.c1 <> col9.c2) AND (col9.c1 <> col9.c3) AND (col9.c2 <> col9.c3) AND (col9.c4 <> col9.c5) AND (col9.c4 <> col9.c6) AND (col9.c5 <> col9.c6) AND (col9.c7 <> col9.c8) AND (col9.c7 <> col9.c9) AND (col9.c8 <> col9.c9);

Finalement, la vue combinée.

USE sudoku;

DROP VIEW IF EXISTS sudoku_memory_combined_view;
CREATE VIEW sudoku_memory_combined_view AS
SELECT t1.*
FROM sudoku_memory_rows_view t1
INNER JOIN sudoku_memory_columns_view t2
ON

-- Jointures entre représentation-colonnes et représentation-rangées
(t1.r1c1 = t2.r1c1) AND (t1.r1c2 = t2.r1c2) AND (t1.r1c3 = t2.r1c3) AND (t1.r1c4 = t2.r1c4) AND
(t1.r1c5 = t2.r1c5) AND (t1.r1c6 = t2.r1c6) AND (t1.r1c7 = t2.r1c7) AND (t1.r1c8 = t2.r1c8) AND
(t1.r1c9 = t2.r1c9) AND (t1.r2c1 = t2.r2c1) AND (t1.r2c2 = t2.r2c2) AND (t1.r2c3 = t2.r2c3) AND
(t1.r2c4 = t2.r2c4) AND (t1.r2c5 = t2.r2c5) AND (t1.r2c6 = t2.r2c6) AND (t1.r2c7 = t2.r2c7) AND
(t1.r2c8 = t2.r2c8) AND (t1.r2c9 = t2.r2c9) AND (t1.r3c1 = t2.r3c1) AND (t1.r3c2 = t2.r3c2) AND
(t1.r3c3 = t2.r3c3) AND (t1.r3c4 = t2.r3c4) AND (t1.r3c5 = t2.r3c5) AND (t1.r3c6 = t2.r3c6) AND
(t1.r3c7 = t2.r3c7) AND (t1.r3c8 = t2.r3c8) AND (t1.r3c9 = t2.r3c9) AND (t1.r4c1 = t2.r4c1) AND
(t1.r4c2 = t2.r4c2) AND (t1.r4c3 = t2.r4c3) AND (t1.r4c4 = t2.r4c4) AND (t1.r4c5 = t2.r4c5) AND
(t1.r4c6 = t2.r4c6) AND (t1.r4c7 = t2.r4c7) AND (t1.r4c8 = t2.r4c8) AND (t1.r4c9 = t2.r4c9) AND
(t1.r5c1 = t2.r5c1) AND (t1.r5c2 = t2.r5c2) AND (t1.r5c3 = t2.r5c3) AND (t1.r5c4 = t2.r5c4) AND
(t1.r5c5 = t2.r5c5) AND (t1.r5c6 = t2.r5c6) AND (t1.r5c7 = t2.r5c7) AND (t1.r5c8 = t2.r5c8) AND
(t1.r5c9 = t2.r5c9) AND (t1.r6c1 = t2.r6c1) AND (t1.r6c2 = t2.r6c2) AND (t1.r6c3 = t2.r6c3) AND
(t1.r6c4 = t2.r6c4) AND (t1.r6c5 = t2.r6c5) AND (t1.r6c6 = t2.r6c6) AND (t1.r6c7 = t2.r6c7) AND
(t1.r6c8 = t2.r6c8) AND (t1.r6c9 = t2.r6c9) AND (t1.r7c1 = t2.r7c1) AND (t1.r7c2 = t2.r7c2) AND
(t1.r7c3 = t2.r7c3) AND (t1.r7c4 = t2.r7c4) AND (t1.r7c5 = t2.r7c5) AND (t1.r7c6 = t2.r7c6) AND
(t1.r7c7 = t2.r7c7) AND (t1.r7c8 = t2.r7c8) AND (t1.r7c9 = t2.r7c9) AND (t1.r8c1 = t2.r8c1) AND
(t1.r8c2 = t2.r8c2) AND (t1.r8c3 = t2.r8c3) AND (t1.r8c4 = t2.r8c4) AND (t1.r8c5 = t2.r8c5) AND
(t1.r8c6 = t2.r8c6) AND (t1.r8c7 = t2.r8c7) AND (t1.r8c8 = t2.r8c8) AND (t1.r8c9 = t2.r8c9) AND
(t1.r9c1 = t2.r9c1) AND (t1.r9c2 = t2.r9c2) AND (t1.r9c3 = t2.r9c3) AND (t1.r9c4 = t2.r9c4) AND
(t1.r9c5 = t2.r9c5) AND (t1.r9c6 = t2.r9c6) AND (t1.r9c7 = t2.r9c7) AND (t1.r9c8 = t2.r9c8) AND
(t1.r9c9 = t2.r9c9);

Réessayons l’exemple du début de cet article pour comparer :


mysql> SELECT *
 -> FROM sudoku_memory_combined_view
 -> WHERE
 -> (r2c2 = 3) AND (r2c3 = 4) AND (r2c4 = 8) AND (r2c5 = 2) AND
 -> (r2c6 = 5) AND (r2c7 = 6) AND (r2c8 = 9) AND (r3c2 = 5) AND
 -> (r3c3 = 9) AND (r3c4 = 3) AND (r3c5 = 6) AND (r3c6 = 4) AND
 -> (r3c7 = 1) AND (r3c8 = 8) AND (r4c2 = 9) AND (r4c3 = 7) AND
 -> (r4c4 = 1) AND (r4c5 = 8) AND (r4c6 = 2) AND (r4c7 = 5) AND
 -> (r4c8 = 6) AND (r6c2 = 8) AND (r6c3 = 1) AND (r6c4 = 4) AND
 -> (r6c5 = 7) AND (r6c6 = 6) AND (r6c7 = 2) AND (r6c8 = 3) AND
 -> (r7c2 = 2) AND (r7c3 = 5) AND (r7c4 = 6) AND (r7c5 = 4) AND
 -> (r7c6 = 1) AND (r7c7 = 9) AND (r7c8 = 7) AND (r8c2 = 7) AND
 -> (r8c3 = 6) AND (r8c4 = 5) AND (r8c5 = 3) AND (r8c6 = 8) AND
 -> (r8c7 = 4) AND (r8c8 = 2);
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
| r1c1 | r1c2 | r1c3 | r1c4 | r1c5 | r1c6 | r1c7 | r1c8 | r1c9 | r2c1 | r2c2 | r2c3 | r2c4 | r2c5 | r2c6 | r2c7 | r2c8 | r2c9 | r3c1 | r3c2 | r3c3 | r3c4 | r3c5 | r3c6 | r3c7 | r3c8 | r3c9 | r4c1 | r4c2 | r4c3 | r4c4 | r4c5 | r4c6 | r4c7 | r4c8 | r4c9 | r5c1 | r5c2 | r5c3 | r5c4 | r5c5 | r5c6 | r5c7 | r5c8 | r5c9 | r6c1 | r6c2 | r6c3 | r6c4 | r6c5 | r6c6 | r6c7 | r6c8 | r6c9 | r7c1 | r7c2 | r7c3 | r7c4 | r7c5 | r7c6 | r7c7 | r7c8 | r7c9 | r8c1 | r8c2 | r8c3 | r8c4 | r8c5 | r8c6 | r8c7 | r8c8 | r8c9 | r9c1 | r9c2 | r9c3 | r9c4 | r9c5 | r9c6 | r9c7 | r9c8 | r9c9 |
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
|   2  |   6  |   8  |   7  |   1  |   9  |   3  |   4  |   5  |   1  |   3  |   4  |   8  |   2  |   5  |   6  |   9  |   7  |   7  |   5  |   9  |   3  |   6  |   4  |   1  |   8  |   2  |   3  |   9  |   7  |   1  |   8  |   2  |   5  |   6  |   4  |   6  |   4  |   2  |   9  |   5  |   3  |   7  |   1  |   8  |   5  |   8  |   1  |   4  |   7  |   6  |   2  |   3  |   9  |   8  |   2  |   5  |   6  |   4  |   1  |   9  |   7  |   3  |   9  |   7  |   6  |   5  |   3  |   8  |   4  |   2  |   1  |   4  |   1  |   3  |   2  |   9  |   7  |   8  |   5  |   6  |
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
1 row in set (0.55 sec)

Wow! Nous sommes passés de 1.5 à 0.55 seconde! Maintenant, qu’en est-il de notre grille à 17 révélés ?

mysql> SELECT *
-> FROM sudoku_memory_combined_view
-> WHERE
-> (r1c8 = 1) AND
-> (r2c1 = 4) AND
-> (r3c2 = 2) AND
-> (r4c5 = 5) AND
-> (r4c7 = 4) AND
-> (r4c9 = 7) AND
-> (r5c3 = 8) AND
-> (r5c7 = 3) AND
-> (r6c3 = 1) AND
-> (r6c5 = 9) AND
-> (r7c1 = 3) AND
-> (r7c4 = 4) AND
-> (r7c7 = 2) AND
-> (r8c2 = 5) AND
-> (r8c4 = 1) AND
-> (r9c4 = 8) AND
-> (r9c6 = 6);
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
| r1c1 | r1c2 | r1c3 | r1c4 | r1c5 | r1c6 | r1c7 | r1c8 | r1c9 | r2c1 | r2c2 | r2c3 | r2c4 | r2c5 | r2c6 | r2c7 | r2c8 | r2c9 | r3c1 | r3c2 | r3c3 | r3c4 | r3c5 | r3c6 | r3c7 | r3c8 | r3c9 | r4c1 | r4c2 | r4c3 | r4c4 | r4c5 | r4c6 | r4c7 | r4c8 | r4c9 | r5c1 | r5c2 | r5c3 | r5c4 | r5c5 | r5c6 | r5c7 | r5c8 | r5c9 | r6c1 | r6c2 | r6c3 | r6c4 | r6c5 | r6c6 | r6c7 | r6c8 | r6c9 | r7c1 | r7c2 | r7c3 | r7c4 | r7c5 | r7c6 | r7c7 | r7c8 | r7c9 | r8c1 | r8c2 | r8c3 | r8c4 | r8c5 | r8c6 | r8c7 | r8c8 | r8c9 | r9c1 | r9c2 | r9c3 | r9c4 | r9c5 | r9c6 | r9c7 | r9c8 | r9c9 |
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
|    6 |    9 |    3 |    7 |    8 |    4 |    5 |    1 |    2 |    4 |    8 |    7 |    5 |    1 |    2 |    9 |    3 |    6 |    1 |    2 |    5 |    9 |    6 |    3 |    8 |    7 |    4 |    9 |    3 |    2 |    6 |    5 |    1 |    4 |    8 |    7 |    5 |    6 |    8 |    2 |    4 |    7 |    3 |    9 |    1 |    7 |    4 |    1 |    3 |    9 |    8 |    6 |    2 |    5 |    3 |    1 |    9 |    4 |    7 |    5 |    2 |    6 |    8 |    8 |    5 |    6 |    1 |    2 |    9 |    7 |    4 |    3 |    2 |    7 |    4 |    8 |    3 |    6 |    1 |    5 |    9 |
+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+------+
1 row in set (7.41 sec)

sudoku17clues

Fantastique!  Nous sommes passés de 20 minutes à 7 secondes!  Mais il y a encore place à amélioration!

5. Presser encore plus fort

Maintenant que nous sommes en mesure d’obtenir des résultats dans des temps raisonnables en utilisant une table de type MEMORY, nous pouvons regarder du côté des variables système pour essayer de les optimiser.

Mais avant de se lancer dans cette entreprise, il importe d’avoir un jeu d’essai afin d’effectuer des tests reproduisibles et mesurables pour vérifier l’impact de chacun des changements sur ces variables.

Nous allons tout d’abord créer une table qui nous permettra de sauvegarder le temps d’exécution de toutes les grilles de notre jeu d’essai.

DROP TABLE IF EXISTS tests;

CREATE TABLE tests (
debut DATETIME,
fin DATETIME
) ENGINE=MYISAM;

Maintenant, nous allons créer notre jeu d’essai.  Évidemment notre échantillon de grilles est varié de façon à être représentatif afin  de mesurer chaque option de façon précise.

USE sudoku;
TRUNCATE tests;
INSERT INTO tests(debut, fin) VALUES (NOW(), NULL);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 1) AND (r1c3 = 3) AND (r1c4 = 7) AND (r1c9 = 5) AND (r2c4 = 6) AND (r2c6 = 4) AND (r3c1 = 8) AND (r4c4 = 8) AND (r4c5 = 1) AND (r5c2 = 9) AND (r5c7 = 7) AND (r6c2 = 6) AND (r6c8 = 9) AND (r7c2 = 2) AND (r7c7 = 4) AND (r8c1 = 5) AND (r8c5 = 3) AND (r9c8 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 8) AND (r1c4 = 3) AND (r1c6 = 7) AND (r2c3 = 9) AND (r3c1 = 2) AND (r3c2 = 7) AND (r3c5 = 4) AND (r4c2 = 3) AND (r4c5 = 1) AND (r5c1 = 4) AND (r5c4 = 9) AND (r5c7 = 2) AND (r5c8 = 8) AND (r6c4 = 6) AND (r6c6 = 2) AND (r6c7 = 4) AND (r6c8 = 3) AND (r7c1 = 3) AND (r7c2 = 1) AND (r7c6 = 6) AND (r8c1 = 6) AND (r8c3 = 8) AND (r8c4 = 1) AND (r8c9 = 7) AND (r9c5 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 2) AND (r1c8 = 1) AND (r2c6 = 2) AND (r2c8 = 3) AND (r2c9 = 4) AND (r3c3 = 3) AND (r3c5 = 5) AND (r4c4 = 4) AND (r4c8 = 6) AND (r5c3 = 2) AND (r5c7 = 9) AND (r6c2 = 5) AND (r6c6 = 8) AND (r7c5 = 3) AND (r7c7 = 5) AND (r8c1 = 7) AND (r8c2 = 9) AND (r8c4 = 1) AND (r9c2 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r2c2 = 8) AND (r3c5 = 5) AND (r3c6 = 3) AND (r3c8 = 8) AND (r3c9 = 9) AND (r4c2 = 2) AND (r4c3 = 4) AND (r4c6 = 9) AND (r5c5 = 1) AND (r5c9 = 5) AND (r6c2 = 1) AND (r6c6 = 7) AND (r7c3 = 2) AND (r7c4 = 1) AND (r7c7 = 3) AND (r8c1 = 9) AND (r8c6 = 5) AND (r8c9 = 7) AND (r9c1 = 5) AND (r9c5 = 8) AND (r9c8 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 5) AND (r1c6 = 8) AND (r1c7 = 6) AND (r2c6 = 6) AND (r2c7 = 2) AND (r2c8 = 7) AND (r3c2 = 1) AND (r4c1 = 9) AND (r4c4 = 7) AND (r4c5 = 6) AND (r4c6 = 2) AND (r5c1 = 7) AND (r6c3 = 8) AND (r7c1 = 2) AND (r7c3 = 3) AND (r7c7 = 8) AND (r8c4 = 1) AND (r8c5 = 9) AND (r8c9 = 5) AND (r9c3 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 5) AND (r1c4 = 8) AND (r1c5 = 3) AND (r2c7 = 7) AND (r2c8 = 1) AND (r3c2 = 3) AND (r4c1 = 7) AND (r4c4 = 4) AND (r4c7 = 8) AND (r5c1 = 1) AND (r5c3 = 2) AND (r7c2 = 8) AND (r7c4 = 6) AND (r7c7 = 4) AND (r8c1 = 9) AND (r8c6 = 2) AND (r9c5 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 7) AND (r1c9 = 5) AND (r2c2 = 3) AND (r2c8 = 7) AND (r3c1 = 2) AND (r3c3 = 5) AND (r3c8 = 3) AND (r3c9 = 8) AND (r4c8 = 8) AND (r4c9 = 9) AND (r5c1 = 5) AND (r5c3 = 8) AND (r5c4 = 2) AND (r5c6 = 9) AND (r5c7 = 7) AND (r5c9 = 4) AND (r6c1 = 3) AND (r7c1 = 6) AND (r7c3 = 4) AND (r7c4 = 9) AND (r7c5 = 8) AND (r7c6 = 7) AND (r7c7 = 5) AND (r8c1 = 9) AND (r8c4 = 5) AND (r9c4 = 4) AND (r9c6 = 6) AND (r9c9 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 4) AND (r1c2 = 6) AND (r1c3 = 8) AND (r1c7 = 1) AND (r2c2 = 7) AND (r2c4 = 4) AND (r2c6 = 8) AND (r2c8 = 5) AND (r3c4 = 6) AND (r4c3 = 6) AND (r4c4 = 1) AND (r4c5 = 8) AND (r4c6 = 3) AND (r4c9 = 7) AND (r5c3 = 7) AND (r6c1 = 3) AND (r6c5 = 5) AND (r6c7 = 2) AND (r6c9 = 1) AND (r7c6 = 7) AND (r8c4 = 8) AND (r8c6 = 2) AND (r8c7 = 5) AND (r9c6 = 5) AND (r9c7 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 9) AND (r1c8 = 1) AND (r2c6 = 2) AND (r2c8 = 3) AND (r2c9 = 4) AND (r3c3 = 5) AND (r3c5 = 6) AND (r4c4 = 3) AND (r4c8 = 7) AND (r5c3 = 2) AND (r5c7 = 6) AND (r6c2 = 1) AND (r6c6 = 5) AND (r7c5 = 8) AND (r7c7 = 2) AND (r8c1 = 7) AND (r8c2 = 3) AND (r8c4 = 9) AND (r9c2 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c6 = 7) AND (r1c9 = 2) AND (r2c5 = 4) AND (r2c6 = 5) AND (r2c8 = 7) AND (r3c3 = 9) AND (r4c1 = 3) AND (r4c5 = 5) AND (r4c7 = 8) AND (r5c1 = 4) AND (r5c2 = 8) AND (r5c4 = 9) AND (r5c6 = 1) AND (r5c9 = 7) AND (r6c3 = 7) AND (r6c6 = 4) AND (r6c7 = 2) AND (r6c9 = 9) AND (r7c5 = 1) AND (r7c7 = 3) AND (r8c8 = 5) AND (r9c2 = 3) AND (r9c4 = 8) AND (r9c5 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 9) AND (r1c8 = 7) AND (r2c8 = 2) AND (r2c9 = 4) AND (r3c1 = 1) AND (r4c2 = 2) AND (r4c3 = 9) AND (r4c9 = 5) AND (r5c6 = 1) AND (r5c7 = 6) AND (r6c2 = 4) AND (r6c5 = 8) AND (r7c4 = 4) AND (r7c5 = 3) AND (r8c1 = 5) AND (r8c7 = 8) AND (r9c4 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r2c2 = 9) AND (r2c3 = 3) AND (r3c2 = 7) AND (r3c8 = 3) AND (r4c3 = 9) AND (r4c5 = 6) AND (r4c8 = 7) AND (r4c9 = 4) AND (r5c3 = 6) AND (r5c5 = 7) AND (r5c7 = 3) AND (r5c8 = 9) AND (r6c2 = 3) AND (r6c4 = 5) AND (r6c7 = 6) AND (r6c8 = 8) AND (r7c1 = 9) AND (r7c5 = 8) AND (r7c6 = 2) AND (r7c7 = 4) AND (r8c2 = 8) AND (r8c3 = 2) AND (r8c5 = 3) AND (r8c8 = 5) AND (r8c9 = 7) AND (r9c2 = 6) AND (r9c3 = 4) AND (r9c4 = 7) AND (r9c5 = 5) AND (r9c8 = 2) AND (r9c9 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 7) AND (r1c5 = 5) AND (r1c8 = 6) AND (r1c9 = 9) AND (r2c1 = 6) AND (r2c8 = 4) AND (r3c2 = 1) AND (r3c5 = 8) AND (r3c6 = 9) AND (r3c9 = 3) AND (r4c4 = 1) AND (r5c4 = 3) AND (r6c2 = 8) AND (r6c8 = 9) AND (r7c1 = 4) AND (r7c2 = 6) AND (r8c3 = 7) AND (r8c6 = 3) AND (r8c9 = 8) AND (r9c2 = 5) AND (r9c3 = 8) AND (r9c4 = 7) AND (r9c6 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 7) AND (r1c5 = 9) AND (r1c6 = 4) AND (r2c2 = 1) AND (r2c6 = 7) AND (r3c3 = 9) AND (r3c4 = 2) AND (r3c5 = 1) AND (r4c1 = 2) AND (r4c4 = 5) AND (r4c6 = 9) AND (r5c3 = 8) AND (r5c4 = 6) AND (r6c1 = 9) AND (r6c2 = 5) AND (r6c6 = 1) AND (r6c8 = 2) AND (r6c9 = 7) AND (r7c1 = 8) AND (r7c6 = 2) AND (r7c7 = 6) AND (r8c1 = 1) AND (r8c5 = 5) AND (r8c6 = 8) AND (r8c9 = 2) AND (r9c4 = 7) AND (r9c5 = 4) AND (r9c9 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 1) AND (r1c4 = 6) AND (r1c5 = 2) AND (r2c1 = 5) AND (r2c8 = 4) AND (r2c9 = 3) AND (r3c5 = 9) AND (r4c1 = 7) AND (r4c8 = 8) AND (r5c3 = 5) AND (r5c9 = 4) AND (r6c4 = 1) AND (r7c6 = 3) AND (r7c7 = 6) AND (r8c2 = 9) AND (r8c7 = 2) AND (r9c1 = 8) AND (r9c6 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 5) AND (r1c3 = 8) AND (r1c6 = 6) AND (r1c7 = 3) AND (r1c8 = 2) AND (r1c9 = 4) AND (r2c1 = 9) AND (r2c2 = 2) AND (r2c3 = 3) AND (r2c6 = 8) AND (r2c7 = 5) AND (r2c8 = 6) AND (r3c5 = 5) AND (r4c9 = 8) AND (r5c2 = 8) AND (r5c3 = 7) AND (r5c6 = 9) AND (r7c2 = 4) AND (r7c4 = 6) AND (r7c6 = 7) AND (r7c8 = 5) AND (r8c1 = 3) AND (r8c5 = 9) AND (r8c6 = 5) AND (r8c8 = 8) AND (r8c9 = 2) AND (r9c2 = 9) AND (r9c3 = 5) AND (r9c5 = 8) AND (r9c7 = 6) AND (r9c8 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 3) AND (r1c5 = 7) AND (r1c7 = 8) AND (r2c4 = 4) AND (r2c6 = 3) AND (r3c1 = 2) AND (r3c4 = 5) AND (r3c5 = 6) AND (r3c6 = 8) AND (r3c9 = 3) AND (r4c2 = 6) AND (r4c3 = 2) AND (r4c7 = 5) AND (r4c8 = 3) AND (r5c1 = 1) AND (r5c3 = 5) AND (r5c7 = 9) AND (r5c9 = 4) AND (r6c2 = 3) AND (r6c3 = 9) AND (r6c7 = 2) AND (r6c8 = 1) AND (r7c1 = 3) AND (r7c4 = 6) AND (r7c5 = 2) AND (r7c6 = 7) AND (r7c9 = 5) AND (r8c4 = 9) AND (r8c6 = 5) AND (r9c3 = 7) AND (r9c5 = 8) AND (r9c7 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 3) AND (r1c3 = 8) AND (r2c1 = 7) AND (r2c6 = 8) AND (r3c1 = 6) AND (r3c2 = 4) AND (r3c3 = 9) AND (r3c4 = 3) AND (r3c5 = 1) AND (r3c6 = 7) AND (r3c8 = 2) AND (r4c1 = 1) AND (r4c2 = 7) AND (r4c5 = 3) AND (r4c6 = 6) AND (r4c8 = 8) AND (r4c9 = 2) AND (r5c1 = 3) AND (r5c3 = 6) AND (r5c4 = 2) AND (r5c6 = 1) AND (r5c8 = 7) AND (r5c9 = 9) AND (r6c5 = 7) AND (r7c1 = 4) AND (r7c2 = 9) AND (r7c8 = 1) AND (r8c2 = 6) AND (r8c3 = 1) AND (r8c5 = 9) AND (r8c8 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c6 = 5) AND (r1c8 = 8) AND (r2c2 = 1) AND (r2c6 = 3) AND (r3c1 = 3) AND (r3c3 = 7) AND (r3c4 = 6) AND (r4c2 = 9) AND (r4c4 = 1) AND (r4c5 = 7) AND (r4c6 = 6) AND (r4c7 = 3) AND (r5c4 = 9) AND (r5c6 = 8) AND (r5c8 = 1) AND (r6c1 = 2) AND (r7c2 = 6) AND (r8c2 = 8) AND (r8c6 = 1) AND (r8c8 = 6) AND (r9c2 = 3) AND (r9c4 = 2) AND (r9c9 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 8) AND (r1c7 = 4) AND (r1c9 = 3) AND (r2c1 = 9) AND (r2c4 = 3) AND (r2c7 = 7) AND (r3c2 = 1) AND (r3c3 = 5) AND (r3c6 = 2) AND (r4c1 = 6) AND (r4c8 = 9) AND (r4c9 = 5) AND (r5c2 = 3) AND (r5c3 = 7) AND (r6c4 = 8) AND (r7c7 = 8) AND (r7c8 = 3) AND (r7c9 = 2) AND (r8c2 = 2) AND (r8c5 = 9) AND (r9c1 = 8) AND (r9c4 = 7) AND (r9c9 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 7) AND (r1c4 = 2) AND (r1c6 = 4) AND (r1c8 = 5) AND (r2c2 = 4) AND (r2c9 = 2) AND (r3c2 = 2) AND (r3c5 = 8) AND (r3c9 = 6) AND (r4c3 = 7) AND (r4c9 = 5) AND (r5c1 = 8) AND (r5c4 = 5) AND (r6c1 = 6) AND (r6c3 = 3) AND (r6c8 = 7) AND (r7c3 = 9) AND (r7c4 = 7) AND (r8c1 = 3) AND (r8c3 = 2) AND (r8c5 = 5) AND (r8c8 = 6) AND (r9c3 = 5) AND (r9c4 = 3) AND (r9c7 = 9) AND (r9c8 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c7 = 8) AND (r1c8 = 7) AND (r2c1 = 2) AND (r2c2 = 6) AND (r3c2 = 4) AND (r3c5 = 6) AND (r3c6 = 5) AND (r4c3 = 7) AND (r5c6 = 2) AND (r5c8 = 3) AND (r6c6 = 3) AND (r6c8 = 4) AND (r6c9 = 5) AND (r7c4 = 3) AND (r8c3 = 2) AND (r8c4 = 8) AND (r8c5 = 9) AND (r8c6 = 7) AND (r9c2 = 5) AND (r9c9 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 3) AND (r1c5 = 8) AND (r1c8 = 7) AND (r1c9 = 1) AND (r2c2 = 6) AND (r2c3 = 7) AND (r3c1 = 8) AND (r5c1 = 7) AND (r5c2 = 2) AND (r5c3 = 9) AND (r5c5 = 3) AND (r5c6 = 1) AND (r5c8 = 6) AND (r5c9 = 4) AND (r6c1 = 3) AND (r6c2 = 8) AND (r6c3 = 1) AND (r7c3 = 8) AND (r7c5 = 1) AND (r7c7 = 7) AND (r7c8 = 4) AND (r8c2 = 1) AND (r8c3 = 2) AND (r8c4 = 6) AND (r8c8 = 8) AND (r8c9 = 3) AND (r9c1 = 6) AND (r9c4 = 3) AND (r9c5 = 4) AND (r9c8 = 1) AND (r9c9 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c8 = 4) AND (r2c5 = 8) AND (r2c9 = 7) AND (r3c4 = 1) AND (r3c5 = 4) AND (r3c6 = 6) AND (r3c7 = 9) AND (r3c9 = 8) AND (r4c1 = 2) AND (r4c5 = 6) AND (r4c9 = 3) AND (r5c3 = 1) AND (r5c5 = 9) AND (r5c9 = 6) AND (r6c2 = 8) AND (r6c3 = 6) AND (r6c4 = 3) AND (r6c5 = 7) AND (r6c7 = 4) AND (r7c5 = 1) AND (r7c7 = 7) AND (r8c1 = 9) AND (r8c2 = 4) AND (r8c8 = 3) AND (r8c9 = 1) AND (r9c6 = 7) AND (r9c9 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 3) AND (r1c5 = 2) AND (r1c6 = 6) AND (r2c7 = 4) AND (r2c9 = 1) AND (r3c1 = 5) AND (r4c1 = 2) AND (r4c8 = 6) AND (r5c6 = 5) AND (r5c8 = 3) AND (r6c2 = 4) AND (r6c4 = 1) AND (r7c4 = 4) AND (r7c5 = 1) AND (r7c7 = 7) AND (r8c4 = 8) AND (r9c1 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 4) AND (r1c7 = 8) AND (r1c8 = 1) AND (r2c1 = 9) AND (r2c4 = 6) AND (r2c6 = 7) AND (r3c3 = 8) AND (r3c6 = 2) AND (r3c8 = 6) AND (r4c6 = 1) AND (r4c8 = 4) AND (r4c9 = 2) AND (r5c2 = 3) AND (r6c1 = 6) AND (r6c2 = 4) AND (r7c1 = 8) AND (r7c2 = 1) AND (r8c7 = 4) AND (r8c8 = 3) AND (r9c3 = 7) AND (r9c4 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 3) AND (r1c3 = 4) AND (r1c6 = 5) AND (r1c8 = 8) AND (r2c2 = 5) AND (r2c5 = 9) AND (r2c8 = 4) AND (r2c9 = 3) AND (r3c1 = 9) AND (r3c2 = 8) AND (r3c4 = 2) AND (r3c9 = 5) AND (r4c1 = 3) AND (r4c5 = 7) AND (r4c9 = 8) AND (r5c2 = 4) AND (r5c6 = 3) AND (r5c7 = 6) AND (r5c8 = 9) AND (r6c2 = 9) AND (r6c5 = 6) AND (r6c7 = 2) AND (r7c1 = 6) AND (r7c5 = 5) AND (r7c6 = 7) AND (r8c5 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 2) AND (r1c5 = 5) AND (r1c6 = 4) AND (r1c7 = 3) AND (r1c8 = 6) AND (r1c9 = 1) AND (r2c4 = 2) AND (r3c5 = 1) AND (r3c6 = 9) AND (r4c4 = 4) AND (r4c6 = 8) AND (r5c2 = 4) AND (r5c4 = 3) AND (r5c5 = 2) AND (r5c6 = 5) AND (r5c7 = 1) AND (r5c8 = 8) AND (r6c5 = 6) AND (r6c8 = 9) AND (r6c9 = 4) AND (r7c1 = 3) AND (r7c4 = 1) AND (r7c6 = 2) AND (r7c9 = 5) AND (r8c9 = 3) AND (r9c6 = 6) AND (r9c7 = 2) AND (r9c8 = 1) AND (r9c9 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 1) AND (r1c5 = 6) AND (r2c2 = 3) AND (r2c7 = 5) AND (r2c9 = 4) AND (r3c5 = 2) AND (r4c8 = 7) AND (r4c9 = 2) AND (r5c3 = 1) AND (r5c4 = 5) AND (r5c5 = 7) AND (r5c7 = 9) AND (r6c2 = 4) AND (r6c8 = 1) AND (r7c2 = 9) AND (r7c3 = 2) AND (r8c4 = 7) AND (r8c7 = 6) AND (r8c8 = 3) AND (r9c8 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 8) AND (r1c3 = 5) AND (r1c9 = 2) AND (r2c4 = 9) AND (r2c6 = 1) AND (r3c1 = 3) AND (r4c2 = 6) AND (r4c4 = 7) AND (r4c7 = 4) AND (r5c1 = 2) AND (r5c5 = 5) AND (r6c8 = 6) AND (r7c4 = 3) AND (r7c5 = 8) AND (r8c2 = 1) AND (r8c7 = 7) AND (r9c2 = 4) AND (r9c8 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r2c2 = 7) AND (r2c7 = 8) AND (r2c9 = 4) AND (r3c5 = 9) AND (r3c6 = 8) AND (r3c7 = 3) AND (r3c9 = 2) AND (r4c1 = 6) AND (r4c4 = 1) AND (r4c7 = 9) AND (r5c3 = 7) AND (r5c8 = 3) AND (r6c1 = 2) AND (r6c2 = 8) AND (r6c6 = 3) AND (r6c7 = 6) AND (r7c2 = 3) AND (r7c4 = 9) AND (r7c5 = 4) AND (r7c6 = 6) AND (r7c9 = 8) AND (r8c2 = 2) AND (r9c1 = 1) AND (r9c3 = 4) AND (r9c4 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 6) AND (r1c8 = 1) AND (r2c6 = 2) AND (r2c8 = 3) AND (r2c9 = 4) AND (r3c3 = 2) AND (r3c5 = 5) AND (r4c4 = 6) AND (r4c8 = 7) AND (r5c3 = 8) AND (r5c7 = 9) AND (r6c2 = 5) AND (r6c6 = 3) AND (r7c5 = 6) AND (r7c7 = 5) AND (r8c1 = 7) AND (r8c2 = 1) AND (r8c4 = 9) AND (r9c2 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 8) AND (r1c3 = 3) AND (r1c7 = 6) AND (r1c8 = 4) AND (r2c1 = 1) AND (r2c2 = 2) AND (r2c5 = 6) AND (r2c7 = 5) AND (r3c1 = 5) AND (r3c4 = 8) AND (r3c5 = 9) AND (r3c6 = 3) AND (r3c8 = 2) AND (r3c9 = 1) AND (r4c5 = 3) AND (r5c2 = 6) AND (r5c5 = 2) AND (r5c6 = 5) AND (r5c8 = 1) AND (r5c9 = 3) AND (r6c2 = 1) AND (r6c6 = 9) AND (r6c8 = 5) AND (r7c1 = 4) AND (r7c4 = 3) AND (r7c6 = 1) AND (r8c2 = 5) AND (r9c4 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 5) AND (r1c3 = 3) AND (r1c5 = 9) AND (r2c7 = 8) AND (r2c9 = 1) AND (r3c1 = 2) AND (r4c1 = 4) AND (r4c5 = 2) AND (r4c8 = 5) AND (r5c2 = 1) AND (r5c4 = 8) AND (r6c2 = 6) AND (r6c4 = 7) AND (r7c4 = 4) AND (r7c6 = 7) AND (r7c7 = 6) AND (r8c8 = 3) AND (r9c1 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 1) AND (r1c4 = 7) AND (r1c7 = 2) AND (r1c9 = 5) AND (r2c8 = 6) AND (r2c9 = 3) AND (r3c3 = 3) AND (r3c5 = 6) AND (r4c1 = 5) AND (r4c4 = 3) AND (r4c9 = 7) AND (r6c3 = 8) AND (r6c4 = 2) AND (r6c6 = 7) AND (r6c7 = 3) AND (r6c8 = 9) AND (r7c8 = 7) AND (r8c1 = 2) AND (r8c4 = 5) AND (r8c7 = 1) AND (r9c2 = 6) AND (r9c4 = 8) AND (r9c5 = 3) AND (r9c6 = 1) AND (r9c7 = 5) AND (r9c9 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 9) AND (r1c4 = 5) AND (r1c6 = 6) AND (r1c7 = 4) AND (r1c8 = 2) AND (r2c1 = 2) AND (r2c2 = 3) AND (r2c7 = 8) AND (r2c9 = 5) AND (r3c2 = 5) AND (r3c3 = 4) AND (r3c5 = 3) AND (r3c8 = 6) AND (r3c9 = 9) AND (r4c3 = 8) AND (r4c4 = 6) AND (r4c5 = 7) AND (r4c6 = 5) AND (r6c4 = 3) AND (r6c5 = 2) AND (r6c6 = 9) AND (r6c9 = 6) AND (r7c2 = 4) AND (r7c3 = 2) AND (r7c5 = 9) AND (r7c6 = 3) AND (r7c7 = 6) AND (r8c4 = 4) AND (r8c5 = 6) AND (r9c1 = 3) AND (r9c4 = 2) AND (r9c6 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 3) AND (r1c5 = 5) AND (r2c3 = 9) AND (r2c7 = 1) AND (r3c6 = 9) AND (r3c9 = 6) AND (r4c4 = 8) AND (r4c9 = 5) AND (r5c5 = 1) AND (r5c7 = 8) AND (r5c8 = 3) AND (r6c2 = 3) AND (r6c3 = 2) AND (r6c8 = 7) AND (r7c1 = 1) AND (r7c2 = 8) AND (r7c7 = 3) AND (r8c3 = 7) AND (r8c8 = 2) AND (r9c2 = 5) AND (r9c7 = 7) AND (r9c9 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 6) AND (r1c7 = 8) AND (r1c9 = 7) AND (r2c3 = 3) AND (r2c8 = 4) AND (r3c1 = 2) AND (r3c2 = 9) AND (r3c5 = 7) AND (r3c9 = 6) AND (r4c4 = 9) AND (r4c7 = 2) AND (r4c9 = 3) AND (r5c4 = 2) AND (r5c5 = 6) AND (r5c9 = 9) AND (r7c1 = 3) AND (r7c2 = 8) AND (r7c5 = 2) AND (r8c3 = 7) AND (r8c7 = 1) AND (r8c9 = 4) AND (r9c4 = 1) AND (r9c8 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 4) AND (r1c8 = 1) AND (r2c6 = 1) AND (r2c8 = 2) AND (r2c9 = 3) AND (r3c5 = 5) AND (r4c4 = 6) AND (r4c8 = 4) AND (r5c3 = 3) AND (r5c7 = 5) AND (r6c2 = 7) AND (r6c6 = 2) AND (r7c5 = 4) AND (r7c7 = 8) AND (r8c1 = 2) AND (r8c2 = 1) AND (r8c4 = 8) AND (r8c8 = 7) AND (r9c2 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 5) AND (r1c5 = 7) AND (r1c7 = 4) AND (r1c8 = 1) AND (r2c3 = 7) AND (r2c4 = 2) AND (r2c7 = 3) AND (r2c9 = 9) AND (r3c5 = 4) AND (r3c7 = 7) AND (r3c9 = 2) AND (r4c3 = 8) AND (r4c6 = 2) AND (r5c4 = 3) AND (r5c5 = 9) AND (r5c7 = 2) AND (r5c8 = 4) AND (r6c2 = 3) AND (r6c4 = 4) AND (r6c9 = 5) AND (r7c4 = 9) AND (r7c5 = 2) AND (r7c7 = 5) AND (r8c4 = 8) AND (r8c5 = 1) AND (r8c6 = 4) AND (r8c9 = 7) AND (r9c1 = 8) AND (r9c6 = 5);
SELECT * FROM sudoku_memory_combined_view WHERE (r2c2 = 7) AND (r2c4 = 6) AND (r2c5 = 3) AND (r3c3 = 9) AND (r3c4 = 8) AND (r3c8 = 6) AND (r4c7 = 7) AND (r4c8 = 3) AND (r5c3 = 2) AND (r5c4 = 3) AND (r5c7 = 5) AND (r5c9 = 9) AND (r6c3 = 6) AND (r6c5 = 1) AND (r6c7 = 2) AND (r7c1 = 2) AND (r7c3 = 3) AND (r7c6 = 1) AND (r8c1 = 9) AND (r8c5 = 6) AND (r8c9 = 8) AND (r9c2 = 8) AND (r9c3 = 1) AND (r9c4 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 9) AND (r2c4 = 3) AND (r2c5 = 6) AND (r2c7 = 1) AND (r3c5 = 1) AND (r3c6 = 9) AND (r3c7 = 5) AND (r4c1 = 5) AND (r4c8 = 9) AND (r4c9 = 2) AND (r5c5 = 7) AND (r6c4 = 6) AND (r6c9 = 3) AND (r7c4 = 9) AND (r7c7 = 7) AND (r7c8 = 5) AND (r8c5 = 5) AND (r8c6 = 1) AND (r8c8 = 2) AND (r9c2 = 6) AND (r9c5 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 3) AND (r1c3 = 7) AND (r2c1 = 9) AND (r2c2 = 4) AND (r2c3 = 6) AND (r2c9 = 3) AND (r3c1 = 1) AND (r3c4 = 7) AND (r4c1 = 2) AND (r4c2 = 8) AND (r4c3 = 1) AND (r4c4 = 4) AND (r5c3 = 3) AND (r5c6 = 6) AND (r6c1 = 4) AND (r7c5 = 1) AND (r7c7 = 9) AND (r7c9 = 2) AND (r8c3 = 2) AND (r8c4 = 9) AND (r8c6 = 4) AND (r8c9 = 6) AND (r9c1 = 3) AND (r9c2 = 1) AND (r9c5 = 8) AND (r9c8 = 4) AND (r9c9 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r2c1 = 4) AND (r2c2 = 2) AND (r2c3 = 9) AND (r2c5 = 8) AND (r2c6 = 3) AND (r3c2 = 8) AND (r3c4 = 5) AND (r3c6 = 4) AND (r4c5 = 2) AND (r4c7 = 4) AND (r4c8 = 7) AND (r5c2 = 4) AND (r5c4 = 8) AND (r5c6 = 9) AND (r5c8 = 5) AND (r6c3 = 2) AND (r6c4 = 1) AND (r6c7 = 3) AND (r6c9 = 8) AND (r7c2 = 9) AND (r8c1 = 8) AND (r8c5 = 7) AND (r8c6 = 2) AND (r8c9 = 4) AND (r9c4 = 9) AND (r9c5 = 1) AND (r9c6 = 8) AND (r9c9 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 2) AND (r1c7 = 4) AND (r1c9 = 9) AND (r2c2 = 4) AND (r2c8 = 5) AND (r2c9 = 2) AND (r3c3 = 5) AND (r3c7 = 8) AND (r3c8 = 7) AND (r4c2 = 8) AND (r4c8 = 9) AND (r4c9 = 6) AND (r5c3 = 7) AND (r5c6 = 9) AND (r5c7 = 2) AND (r5c8 = 3) AND (r6c3 = 2) AND (r6c5 = 3) AND (r6c7 = 7) AND (r6c9 = 8) AND (r7c2 = 5) AND (r7c5 = 8) AND (r7c7 = 9) AND (r8c1 = 2) AND (r8c3 = 6) AND (r9c3 = 8) AND (r9c4 = 5) AND (r9c6 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 9) AND (r1c5 = 6) AND (r2c3 = 2) AND (r2c7 = 6) AND (r3c2 = 1) AND (r3c6 = 9) AND (r3c7 = 5) AND (r3c9 = 3) AND (r4c2 = 7) AND (r4c7 = 8) AND (r5c1 = 1) AND (r5c8 = 3) AND (r6c3 = 9) AND (r6c9 = 5) AND (r7c2 = 8) AND (r7c6 = 3) AND (r7c9 = 9) AND (r8c1 = 7) AND (r8c3 = 5) AND (r8c6 = 2) AND (r8c7 = 1) AND (r8c9 = 6) AND (r9c1 = 6) AND (r9c8 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c7 = 3) AND (r1c8 = 1) AND (r2c1 = 7) AND (r2c4 = 5) AND (r3c1 = 2) AND (r3c5 = 4) AND (r4c2 = 3) AND (r4c3 = 9) AND (r4c6 = 8) AND (r5c8 = 6) AND (r5c9 = 2) AND (r6c2 = 1) AND (r7c1 = 5) AND (r7c4 = 6) AND (r7c9 = 7) AND (r8c2 = 8) AND (r8c7 = 9) AND (r9c5 = 5);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 5) AND (r1c3 = 1) AND (r1c5 = 7) AND (r1c8 = 6) AND (r1c9 = 3) AND (r2c2 = 6) AND (r2c8 = 2) AND (r3c2 = 2) AND (r3c3 = 3) AND (r3c5 = 6) AND (r3c7 = 7) AND (r3c8 = 9) AND (r5c2 = 1) AND (r5c7 = 3) AND (r5c8 = 5) AND (r6c3 = 9) AND (r6c8 = 4) AND (r7c1 = 6) AND (r7c4 = 4) AND (r7c6 = 9) AND (r7c7 = 5) AND (r8c1 = 5) AND (r8c2 = 9) AND (r8c4 = 6) AND (r8c5 = 3) AND (r8c8 = 7) AND (r8c9 = 4) AND (r9c3 = 4) AND (r9c4 = 7) AND (r9c5 = 5) AND (r9c8 = 3) AND (r9c9 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 7) AND (r1c8 = 9) AND (r2c6 = 2) AND (r2c8 = 3) AND (r2c9 = 4) AND (r3c3 = 2) AND (r3c5 = 5) AND (r4c4 = 4) AND (r4c8 = 2) AND (r5c3 = 6) AND (r5c7 = 7) AND (r6c2 = 5) AND (r6c6 = 3) AND (r7c5 = 6) AND (r7c7 = 5) AND (r8c1 = 8) AND (r8c2 = 1) AND (r8c4 = 9) AND (r9c2 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 1) AND (r1c8 = 8) AND (r2c6 = 1) AND (r2c8 = 2) AND (r2c9 = 3) AND (r3c3 = 4) AND (r3c5 = 5) AND (r4c4 = 2) AND (r4c8 = 6) AND (r5c3 = 7) AND (r5c7 = 8) AND (r6c2 = 5) AND (r6c6 = 9) AND (r7c5 = 7) AND (r7c7 = 5) AND (r8c1 = 6) AND (r8c2 = 3) AND (r8c4 = 8) AND (r9c2 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 2) AND (r1c3 = 7) AND (r1c5 = 3) AND (r1c6 = 4) AND (r1c8 = 6) AND (r1c9 = 5) AND (r2c6 = 8) AND (r2c9 = 2) AND (r3c3 = 4) AND (r3c7 = 7) AND (r4c1 = 4) AND (r4c9 = 3) AND (r5c1 = 8) AND (r5c3 = 2) AND (r5c7 = 6) AND (r5c8 = 4) AND (r6c2 = 7) AND (r6c9 = 8) AND (r7c2 = 2) AND (r7c3 = 1) AND (r7c5 = 8) AND (r7c8 = 5) AND (r8c1 = 6) AND (r8c2 = 4) AND (r8c5 = 2) AND (r8c6 = 5) AND (r8c7 = 3) AND (r9c1 = 5) AND (r9c6 = 7) AND (r9c9 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c8 = 8) AND (r2c1 = 3) AND (r2c4 = 5) AND (r2c6 = 7) AND (r2c7 = 1) AND (r3c6 = 1) AND (r3c8 = 6) AND (r3c9 = 3) AND (r4c3 = 2) AND (r5c1 = 8) AND (r5c3 = 7) AND (r5c7 = 2) AND (r5c8 = 3) AND (r6c1 = 5) AND (r6c5 = 7) AND (r7c2 = 8) AND (r7c5 = 4) AND (r7c6 = 3) AND (r7c8 = 2) AND (r7c9 = 1) AND (r8c1 = 1) AND (r8c3 = 5) AND (r8c9 = 6) AND (r9c1 = 4) AND (r9c2 = 3) AND (r9c7 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 3) AND (r1c8 = 1) AND (r2c6 = 2) AND (r2c8 = 3) AND (r2c9 = 4) AND (r3c3 = 5) AND (r3c5 = 7) AND (r4c4 = 4) AND (r4c8 = 5) AND (r5c3 = 7) AND (r5c7 = 6) AND (r6c2 = 8) AND (r6c6 = 1) AND (r7c5 = 5) AND (r7c7 = 8) AND (r8c1 = 1) AND (r8c2 = 2) AND (r8c4 = 3) AND (r9c2 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c5 = 3) AND (r1c6 = 1) AND (r2c1 = 3) AND (r2c4 = 4) AND (r2c5 = 2) AND (r2c8 = 6) AND (r3c4 = 6) AND (r3c6 = 9) AND (r4c5 = 7) AND (r4c6 = 3) AND (r4c7 = 4) AND (r5c2 = 7) AND (r5c4 = 1) AND (r5c6 = 2) AND (r5c7 = 5) AND (r5c8 = 3) AND (r6c4 = 5) AND (r6c5 = 4) AND (r6c8 = 1) AND (r7c2 = 1) AND (r7c7 = 3) AND (r8c1 = 5) AND (r8c2 = 3) AND (r8c7 = 6) AND (r8c8 = 9) AND (r9c2 = 6) AND (r9c3 = 9) AND (r9c5 = 1) AND (r9c6 = 4) AND (r9c7 = 2) AND (r9c8 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 8) AND (r1c7 = 4) AND (r2c2 = 2) AND (r2c6 = 1) AND (r2c8 = 9) AND (r3c5 = 7) AND (r3c9 = 5) AND (r4c4 = 4) AND (r4c7 = 8) AND (r5c5 = 5) AND (r5c9 = 7) AND (r6c1 = 1) AND (r6c6 = 9) AND (r6c8 = 2) AND (r7c1 = 9) AND (r7c6 = 6) AND (r7c7 = 1) AND (r7c8 = 3) AND (r8c1 = 2) AND (r9c1 = 6) AND (r9c3 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 3) AND (r1c3 = 4) AND (r1c4 = 6) AND (r1c7 = 9) AND (r1c8 = 2) AND (r1c9 = 1) AND (r2c1 = 2) AND (r3c2 = 1) AND (r3c3 = 9) AND (r3c9 = 5) AND (r4c2 = 4) AND (r4c3 = 2) AND (r4c9 = 9) AND (r5c2 = 9) AND (r5c3 = 6) AND (r6c1 = 3) AND (r6c4 = 9) AND (r6c8 = 6) AND (r7c2 = 2) AND (r7c3 = 1) AND (r7c5 = 4) AND (r7c6 = 9) AND (r7c8 = 5) AND (r8c4 = 5) AND (r8c6 = 6) AND (r8c8 = 1) AND (r9c4 = 2) AND (r9c5 = 1) AND (r9c7 = 7) AND (r9c9 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c9 = 4) AND (r2c2 = 3) AND (r2c3 = 1) AND (r2c6 = 9) AND (r2c9 = 7) AND (r3c1 = 2) AND (r3c2 = 9) AND (r3c6 = 1) AND (r4c2 = 7) AND (r4c6 = 6) AND (r5c6 = 2) AND (r5c9 = 9) AND (r6c4 = 7) AND (r6c5 = 4) AND (r7c1 = 5) AND (r7c5 = 1) AND (r7c8 = 2) AND (r8c2 = 6) AND (r8c5 = 9) AND (r8c8 = 7) AND (r8c9 = 3) AND (r9c3 = 3) AND (r9c8 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 4) AND (r1c6 = 2) AND (r1c7 = 5) AND (r1c8 = 6) AND (r2c4 = 7) AND (r2c9 = 3) AND (r3c2 = 1) AND (r4c1 = 6) AND (r4c5 = 9) AND (r4c6 = 8) AND (r5c5 = 1) AND (r6c9 = 4) AND (r7c7 = 1) AND (r7c8 = 8) AND (r8c1 = 4) AND (r8c4 = 3) AND (r9c1 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 7) AND (r1c4 = 4) AND (r1c5 = 2) AND (r1c6 = 6) AND (r1c7 = 1) AND (r2c2 = 4) AND (r2c4 = 3) AND (r2c5 = 7) AND (r2c8 = 2) AND (r3c3 = 6) AND (r3c5 = 1) AND (r3c6 = 5) AND (r3c8 = 7) AND (r4c1 = 6) AND (r5c2 = 8) AND (r5c4 = 5) AND (r6c1 = 4) AND (r6c2 = 5) AND (r6c3 = 2) AND (r6c5 = 6) AND (r6c6 = 3) AND (r7c1 = 5) AND (r7c4 = 7) AND (r7c9 = 2) AND (r8c1 = 7) AND (r8c9 = 1) AND (r9c1 = 3) AND (r9c3 = 4) AND (r9c4 = 6) AND (r9c5 = 5) AND (r9c6 = 2) AND (r9c9 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 9) AND (r1c7 = 3) AND (r1c9 = 6) AND (r2c1 = 7) AND (r2c4 = 6) AND (r2c6 = 4) AND (r2c7 = 8) AND (r3c1 = 6) AND (r3c2 = 1) AND (r3c5 = 3) AND (r3c9 = 7) AND (r4c1 = 1) AND (r4c2 = 6) AND (r4c7 = 4) AND (r4c9 = 3) AND (r5c6 = 1) AND (r5c7 = 7) AND (r6c2 = 8) AND (r6c4 = 4) AND (r6c5 = 9) AND (r6c8 = 1) AND (r7c2 = 9) AND (r7c5 = 4) AND (r8c9 = 4) AND (r9c1 = 2) AND (r9c2 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 4) AND (r1c2 = 3) AND (r1c5 = 7) AND (r1c6 = 6) AND (r1c7 = 5) AND (r1c8 = 9) AND (r2c2 = 6) AND (r2c3 = 5) AND (r2c5 = 4) AND (r3c4 = 5) AND (r3c5 = 9) AND (r3c7 = 3) AND (r4c2 = 1) AND (r4c6 = 8) AND (r4c7 = 4) AND (r4c8 = 5) AND (r5c1 = 3) AND (r5c2 = 7) AND (r5c4 = 6) AND (r5c6 = 4) AND (r5c7 = 1) AND (r5c9 = 9) AND (r6c5 = 1) AND (r6c6 = 9) AND (r6c8 = 7) AND (r6c9 = 3) AND (r7c2 = 9) AND (r7c5 = 8) AND (r8c2 = 5) AND (r8c5 = 6) AND (r8c6 = 7) AND (r8c7 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 8) AND (r1c2 = 4) AND (r1c6 = 6) AND (r1c8 = 2) AND (r2c3 = 6) AND (r2c9 = 9) AND (r3c7 = 1) AND (r4c5 = 9) AND (r4c8 = 3) AND (r5c1 = 3) AND (r5c2 = 6) AND (r5c7 = 9) AND (r6c3 = 2) AND (r6c4 = 8) AND (r7c2 = 9) AND (r7c7 = 4) AND (r7c8 = 7) AND (r8c2 = 7) AND (r8c3 = 1) AND (r8c5 = 4) AND (r8c7 = 6) AND (r8c9 = 8) AND (r9c1 = 2) AND (r9c9 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 2) AND (r1c4 = 3) AND (r1c6 = 8) AND (r1c8 = 6) AND (r2c1 = 8) AND (r2c5 = 7) AND (r2c9 = 2) AND (r3c3 = 6) AND (r3c4 = 5) AND (r3c6 = 2) AND (r3c7 = 8) AND (r4c1 = 6) AND (r4c3 = 2) AND (r4c7 = 7) AND (r4c9 = 3) AND (r5c2 = 9) AND (r5c8 = 2) AND (r6c1 = 3) AND (r6c3 = 5) AND (r6c7 = 9) AND (r6c9 = 4) AND (r7c3 = 7) AND (r7c4 = 2) AND (r7c6 = 1) AND (r7c7 = 6) AND (r8c1 = 5) AND (r8c5 = 6) AND (r8c9 = 1) AND (r9c2 = 6) AND (r9c4 = 4) AND (r9c6 = 5) AND (r9c8 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 2) AND (r1c3 = 4) AND (r1c8 = 3) AND (r1c9 = 1) AND (r2c1 = 9) AND (r2c3 = 6) AND (r2c4 = 4) AND (r2c5 = 5) AND (r3c3 = 3) AND (r3c5 = 7) AND (r3c8 = 6) AND (r5c1 = 4) AND (r5c8 = 7) AND (r5c9 = 9) AND (r6c4 = 5) AND (r6c5 = 6) AND (r7c1 = 1) AND (r7c4 = 2) AND (r8c1 = 6) AND (r8c2 = 7) AND (r8c5 = 4) AND (r9c5 = 9) AND (r9c6 = 7) AND (r9c8 = 5);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 6) AND (r1c7 = 4) AND (r2c1 = 9) AND (r2c3 = 3) AND (r3c4 = 4) AND (r3c8 = 2) AND (r4c9 = 9) AND (r5c1 = 2) AND (r5c7 = 3) AND (r6c5 = 3) AND (r6c6 = 1) AND (r6c7 = 7) AND (r7c1 = 5) AND (r7c2 = 9) AND (r7c3 = 7) AND (r8c1 = 4) AND (r8c4 = 9) AND (r9c2 = 2) AND (r9c7 = 6) AND (r9c9 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 5) AND (r1c4 = 7) AND (r1c8 = 3) AND (r2c2 = 8) AND (r2c6 = 9) AND (r2c9 = 5) AND (r3c4 = 1) AND (r3c7 = 6) AND (r3c9 = 2) AND (r4c8 = 9) AND (r5c5 = 6) AND (r6c4 = 3) AND (r6c6 = 1) AND (r7c2 = 7) AND (r7c8 = 8) AND (r8c1 = 6) AND (r8c4 = 2) AND (r8c5 = 8) AND (r8c7 = 3) AND (r9c1 = 1) AND (r9c2 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c7 = 7) AND (r2c2 = 4) AND (r2c7 = 1) AND (r2c9 = 3) AND (r3c6 = 9) AND (r3c8 = 6) AND (r3c9 = 5) AND (r4c3 = 4) AND (r5c2 = 3) AND (r5c3 = 7) AND (r5c4 = 2) AND (r5c8 = 9) AND (r6c4 = 1) AND (r7c1 = 7) AND (r7c5 = 1) AND (r7c7 = 6) AND (r8c3 = 5) AND (r8c6 = 7) AND (r8c7 = 2) AND (r9c5 = 6) AND (r9c6 = 5) AND (r9c8 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 2) AND (r1c5 = 3) AND (r1c8 = 5) AND (r2c2 = 8) AND (r2c9 = 1) AND (r3c2 = 9) AND (r4c1 = 5) AND (r4c6 = 1) AND (r4c8 = 3) AND (r5c5 = 8) AND (r5c7 = 9) AND (r6c1 = 2) AND (r7c2 = 4) AND (r7c4 = 6) AND (r7c7 = 8) AND (r8c1 = 7) AND (r8c4 = 5);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 6) AND (r1c5 = 4) AND (r1c6 = 1) AND (r1c7 = 8) AND (r1c9 = 5) AND (r2c3 = 8) AND (r2c6 = 2) AND (r2c7 = 4) AND (r2c9 = 1) AND (r3c1 = 1) AND (r3c3 = 4) AND (r3c4 = 5) AND (r3c5 = 8) AND (r3c8 = 6) AND (r4c3 = 1) AND (r4c5 = 3) AND (r4c9 = 4) AND (r6c6 = 9) AND (r6c9 = 3) AND (r7c2 = 2) AND (r7c3 = 6) AND (r8c1 = 5) AND (r8c3 = 9) AND (r8c5 = 1) AND (r8c6 = 4) AND (r8c8 = 2) AND (r8c9 = 6) AND (r9c1 = 4) AND (r9c5 = 6) AND (r9c9 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 3) AND (r1c4 = 2) AND (r2c1 = 5) AND (r2c5 = 8) AND (r2c7 = 6) AND (r2c9 = 4) AND (r3c9 = 9) AND (r4c1 = 3) AND (r4c4 = 4) AND (r4c5 = 5) AND (r5c3 = 8) AND (r5c4 = 1) AND (r5c5 = 9) AND (r5c6 = 6) AND (r6c1 = 4) AND (r6c5 = 3) AND (r6c7 = 1) AND (r6c9 = 6) AND (r7c1 = 1) AND (r7c4 = 6) AND (r7c7 = 9) AND (r7c8 = 5) AND (r7c9 = 8) AND (r8c4 = 5) AND (r9c1 = 8) AND (r9c2 = 6) AND (r9c7 = 4) AND (r9c9 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 6) AND (r1c3 = 4) AND (r1c4 = 3) AND (r1c5 = 1) AND (r1c9 = 5) AND (r2c2 = 2) AND (r2c5 = 5) AND (r2c7 = 6) AND (r2c9 = 4) AND (r3c3 = 8) AND (r3c5 = 6) AND (r3c6 = 4) AND (r3c8 = 2) AND (r4c3 = 1) AND (r4c7 = 9) AND (r4c9 = 2) AND (r5c2 = 3) AND (r6c1 = 8) AND (r6c5 = 2) AND (r6c6 = 6) AND (r6c9 = 1) AND (r7c4 = 5) AND (r7c5 = 9) AND (r8c1 = 3) AND (r8c6 = 8) AND (r9c1 = 9) AND (r9c5 = 4) AND (r9c6 = 3) AND (r9c8 = 5);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c6 = 1) AND (r1c8 = 7) AND (r1c9 = 3) AND (r2c4 = 5) AND (r2c5 = 6) AND (r2c7 = 8) AND (r2c8 = 4) AND (r3c4 = 3) AND (r3c6 = 8) AND (r3c7 = 6) AND (r4c5 = 5) AND (r4c6 = 2) AND (r4c7 = 7) AND (r4c9 = 6) AND (r5c4 = 7) AND (r5c5 = 1) AND (r5c8 = 3) AND (r7c1 = 2) AND (r7c2 = 7) AND (r7c8 = 6) AND (r7c9 = 8) AND (r8c2 = 4) AND (r8c3 = 5) AND (r8c4 = 1) AND (r9c1 = 6) AND (r9c2 = 8) AND (r9c3 = 3) AND (r9c6 = 7) AND (r9c9 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c5 = 5) AND (r1c8 = 1) AND (r2c1 = 5) AND (r2c2 = 8) AND (r3c5 = 7) AND (r4c4 = 7) AND (r4c5 = 2) AND (r4c6 = 4) AND (r4c7 = 1) AND (r4c8 = 8) AND (r5c1 = 1) AND (r5c5 = 8) AND (r5c9 = 9) AND (r6c2 = 7) AND (r6c4 = 1) AND (r6c5 = 3) AND (r6c8 = 4) AND (r7c1 = 3) AND (r7c3 = 2) AND (r7c5 = 9) AND (r7c7 = 8) AND (r7c8 = 5) AND (r7c9 = 4) AND (r8c2 = 9) AND (r8c3 = 7) AND (r8c7 = 2) AND (r9c1 = 8) AND (r9c3 = 5) AND (r9c6 = 2) AND (r9c8 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 4) AND (r1c6 = 7) AND (r1c9 = 2) AND (r2c1 = 5) AND (r2c2 = 2) AND (r2c4 = 9) AND (r2c5 = 3) AND (r2c7 = 4) AND (r3c4 = 5) AND (r3c9 = 7) AND (r4c1 = 9) AND (r4c2 = 3) AND (r4c9 = 4) AND (r5c9 = 1) AND (r6c6 = 1) AND (r6c7 = 3) AND (r7c3 = 4) AND (r7c5 = 2) AND (r8c1 = 2) AND (r8c2 = 9) AND (r8c5 = 7) AND (r9c1 = 1) AND (r9c5 = 8) AND (r9c6 = 5) AND (r9c8 = 2) AND (r9c9 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 4) AND (r1c7 = 7) AND (r1c8 = 5) AND (r1c9 = 3) AND (r2c2 = 7) AND (r2c3 = 9) AND (r2c6 = 3) AND (r2c7 = 2) AND (r2c8 = 1) AND (r3c3 = 5) AND (r4c5 = 2) AND (r5c3 = 4) AND (r5c5 = 3) AND (r5c7 = 1) AND (r5c9 = 7) AND (r6c1 = 3) AND (r6c3 = 6) AND (r6c4 = 1) AND (r6c7 = 4) AND (r6c8 = 2) AND (r7c1 = 2) AND (r7c3 = 3) AND (r7c6 = 6) AND (r7c7 = 5) AND (r7c9 = 1) AND (r8c2 = 6) AND (r8c3 = 7) AND (r8c5 = 1) AND (r8c8 = 4) AND (r8c9 = 2) AND (r9c7 = 6) AND (r9c8 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 3) AND (r1c3 = 7) AND (r1c8 = 5) AND (r2c3 = 9) AND (r2c5 = 6) AND (r2c8 = 1) AND (r3c6 = 1) AND (r3c7 = 3) AND (r4c2 = 7) AND (r5c3 = 1) AND (r5c4 = 2) AND (r5c6 = 7) AND (r5c9 = 5) AND (r6c5 = 3) AND (r6c7 = 8) AND (r6c9 = 6) AND (r7c6 = 3) AND (r8c4 = 7) AND (r8c5 = 8) AND (r9c1 = 6) AND (r9c8 = 9) AND (r9c9 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 3) AND (r1c7 = 5) AND (r1c8 = 9) AND (r2c2 = 5) AND (r2c3 = 1) AND (r2c5 = 6) AND (r2c6 = 3) AND (r3c3 = 9) AND (r3c5 = 2) AND (r5c2 = 7) AND (r5c3 = 3) AND (r5c5 = 5) AND (r5c8 = 2) AND (r6c3 = 2) AND (r6c7 = 1) AND (r6c8 = 7) AND (r7c2 = 9) AND (r7c4 = 7) AND (r7c6 = 6) AND (r7c7 = 3) AND (r7c8 = 5) AND (r8c1 = 7) AND (r8c2 = 8) AND (r9c5 = 8) AND (r9c9 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r2c4 = 4) AND (r2c8 = 5) AND (r3c1 = 8) AND (r3c2 = 5) AND (r3c3 = 9) AND (r3c4 = 2) AND (r4c3 = 3) AND (r4c4 = 5) AND (r4c7 = 4) AND (r4c8 = 9) AND (r5c7 = 5) AND (r5c9 = 6) AND (r6c3 = 7) AND (r6c4 = 9) AND (r6c5 = 2) AND (r6c6 = 4) AND (r6c8 = 3) AND (r6c9 = 8) AND (r7c6 = 2) AND (r7c8 = 8) AND (r8c1 = 7) AND (r8c4 = 8) AND (r8c5 = 5) AND (r8c7 = 9) AND (r8c8 = 4) AND (r9c2 = 3) AND (r9c4 = 7) AND (r9c5 = 4) AND (r9c8 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 9) AND (r1c7 = 6) AND (r2c1 = 8) AND (r2c3 = 6) AND (r2c4 = 7) AND (r2c5 = 4) AND (r2c6 = 5) AND (r2c8 = 2) AND (r2c9 = 9) AND (r3c3 = 4) AND (r3c6 = 3) AND (r3c8 = 7) AND (r3c9 = 5) AND (r4c1 = 4) AND (r4c4 = 3) AND (r4c5 = 7) AND (r4c6 = 9) AND (r4c8 = 6) AND (r5c6 = 4) AND (r6c1 = 7) AND (r6c5 = 8) AND (r6c8 = 5) AND (r7c3 = 8) AND (r7c4 = 4) AND (r7c6 = 6) AND (r8c1 = 3) AND (r8c5 = 5) AND (r8c6 = 8) AND (r9c4 = 2) AND (r9c5 = 3) AND (r9c9 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c5 = 7) AND (r3c3 = 3) AND (r3c5 = 2) AND (r3c8 = 5) AND (r4c2 = 6) AND (r4c5 = 4) AND (r4c9 = 2) AND (r5c3 = 8) AND (r5c4 = 5) AND (r5c6 = 9) AND (r6c4 = 6) AND (r7c1 = 6) AND (r7c8 = 9) AND (r8c3 = 2) AND (r8c5 = 3) AND (r8c9 = 4) AND (r9c1 = 4) AND (r9c2 = 7) AND (r9c4 = 8) AND (r9c7 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 3) AND (r1c4 = 4) AND (r1c6 = 6) AND (r2c2 = 9) AND (r2c7 = 7) AND (r4c1 = 6) AND (r4c3 = 4) AND (r4c4 = 1) AND (r5c5 = 7) AND (r5c7 = 2) AND (r5c9 = 9) AND (r6c7 = 5) AND (r7c5 = 3) AND (r7c8 = 8) AND (r8c1 = 5) AND (r8c2 = 2) AND (r9c4 = 8) AND (r9c8 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 7) AND (r1c5 = 2) AND (r2c2 = 8) AND (r2c6 = 6) AND (r3c6 = 3) AND (r3c9 = 6) AND (r4c3 = 3) AND (r4c5 = 4) AND (r4c7 = 7) AND (r4c8 = 8) AND (r5c1 = 2) AND (r5c5 = 1) AND (r6c2 = 6) AND (r6c9 = 5) AND (r7c4 = 1) AND (r7c7 = 3) AND (r7c8 = 7) AND (r8c5 = 5) AND (r9c3 = 8) AND (r9c6 = 7) AND (r9c8 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c8 = 8) AND (r2c1 = 3) AND (r2c2 = 5) AND (r2c3 = 1) AND (r2c5 = 7) AND (r3c6 = 9) AND (r3c7 = 7) AND (r3c9 = 3) AND (r4c3 = 7) AND (r4c4 = 1) AND (r4c6 = 8) AND (r4c7 = 5) AND (r5c5 = 3) AND (r5c7 = 2) AND (r6c2 = 8) AND (r6c6 = 5) AND (r6c8 = 9) AND (r7c7 = 1) AND (r7c8 = 5) AND (r7c9 = 2) AND (r8c3 = 3) AND (r8c4 = 4) AND (r8c6 = 1) AND (r9c4 = 9) AND (r9c5 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c7 = 3) AND (r1c9 = 8) AND (r2c1 = 7) AND (r2c2 = 2) AND (r2c4 = 9) AND (r2c9 = 6) AND (r3c4 = 1) AND (r4c2 = 8) AND (r4c6 = 6) AND (r5c3 = 7) AND (r5c5 = 5) AND (r5c8 = 6) AND (r6c1 = 3) AND (r6c5 = 2) AND (r7c1 = 5) AND (r7c3 = 8) AND (r7c4 = 7) AND (r7c5 = 1) AND (r8c6 = 9) AND (r9c1 = 2) AND (r9c3 = 6) AND (r9c9 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 5) AND (r1c3 = 2) AND (r1c4 = 9) AND (r2c7 = 8) AND (r3c8 = 4) AND (r3c9 = 6) AND (r4c2 = 1) AND (r4c6 = 2) AND (r4c9 = 3) AND (r5c1 = 3) AND (r5c2 = 7) AND (r6c6 = 4) AND (r7c8 = 7) AND (r8c1 = 6) AND (r8c4 = 5) AND (r8c6 = 1) AND (r9c1 = 4) AND (r9c4 = 3) AND (r9c6 = 9) AND (r9c7 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 7) AND (r1c5 = 6) AND (r1c6 = 4) AND (r1c8 = 2) AND (r1c9 = 5) AND (r2c2 = 5) AND (r2c6 = 9) AND (r2c9 = 1) AND (r3c5 = 2) AND (r3c8 = 4) AND (r3c9 = 9) AND (r4c1 = 5) AND (r4c3 = 6) AND (r4c6 = 3) AND (r4c8 = 1) AND (r5c1 = 4) AND (r5c3 = 2) AND (r6c2 = 1) AND (r7c1 = 3) AND (r7c2 = 6) AND (r7c3 = 9) AND (r7c4 = 4) AND (r7c8 = 5) AND (r8c3 = 5) AND (r8c6 = 6) AND (r9c1 = 7) AND (r9c9 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 9) AND (r1c5 = 6) AND (r1c6 = 5) AND (r1c9 = 7) AND (r2c1 = 5) AND (r2c6 = 3) AND (r2c8 = 6) AND (r2c9 = 8) AND (r3c3 = 8) AND (r3c4 = 4) AND (r3c9 = 9) AND (r4c3 = 2) AND (r5c5 = 5) AND (r5c9 = 3) AND (r6c3 = 6) AND (r6c6 = 7) AND (r7c5 = 9) AND (r7c7 = 2) AND (r8c4 = 3) AND (r8c7 = 4) AND (r9c1 = 6) AND (r9c8 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 7) AND (r1c4 = 3) AND (r1c8 = 6) AND (r2c5 = 8) AND (r2c7 = 5) AND (r3c2 = 1) AND (r4c1 = 8) AND (r4c3 = 9) AND (r4c4 = 6) AND (r4c7 = 4) AND (r5c4 = 1) AND (r5c6 = 2) AND (r6c1 = 5) AND (r7c4 = 7) AND (r7c8 = 3) AND (r7c9 = 2) AND (r8c1 = 4) AND (r8c5 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c6 = 4) AND (r1c8 = 6) AND (r2c4 = 1) AND (r2c5 = 2) AND (r2c6 = 9) AND (r2c8 = 8) AND (r2c9 = 4) AND (r3c3 = 2) AND (r4c3 = 5) AND (r4c7 = 4) AND (r5c2 = 2) AND (r5c4 = 4) AND (r5c5 = 1) AND (r5c7 = 8) AND (r5c8 = 5) AND (r6c2 = 6) AND (r6c4 = 5) AND (r6c6 = 8) AND (r6c8 = 2) AND (r7c1 = 2) AND (r7c2 = 1) AND (r7c3 = 6) AND (r7c6 = 5) AND (r8c2 = 8) AND (r8c4 = 2) AND (r8c5 = 3) AND (r9c2 = 3) AND (r9c3 = 4) AND (r9c4 = 8) AND (r9c6 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 8) AND (r1c7 = 1) AND (r1c9 = 4) AND (r2c1 = 7) AND (r2c2 = 3) AND (r4c5 = 7) AND (r4c6 = 2) AND (r4c7 = 6) AND (r5c2 = 1) AND (r5c3 = 3) AND (r7c3 = 4) AND (r7c4 = 3) AND (r7c5 = 1) AND (r8c1 = 2) AND (r8c7 = 5) AND (r8c8 = 7) AND (r9c8 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 9) AND (r1c5 = 4) AND (r1c8 = 8) AND (r2c2 = 4) AND (r2c9 = 7) AND (r3c4 = 6) AND (r3c9 = 2) AND (r4c3 = 5) AND (r4c7 = 7) AND (r4c8 = 4) AND (r5c1 = 9) AND (r5c2 = 6) AND (r5c7 = 5) AND (r6c4 = 2) AND (r7c2 = 5) AND (r7c5 = 2) AND (r7c9 = 8) AND (r8c3 = 4) AND (r8c5 = 8) AND (r8c6 = 3) AND (r9c2 = 8) AND (r9c4 = 9) AND (r9c5 = 7) AND (r9c8 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 2) AND (r1c5 = 6) AND (r1c8 = 8) AND (r2c1 = 9) AND (r2c3 = 4) AND (r4c2 = 8) AND (r4c4 = 5) AND (r4c8 = 6) AND (r5c1 = 7) AND (r5c6 = 9) AND (r6c9 = 1) AND (r7c2 = 2) AND (r7c4 = 6) AND (r8c5 = 3) AND (r8c7 = 9) AND (r9c1 = 1) AND (r9c7 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 4) AND (r1c3 = 8) AND (r1c4 = 9) AND (r1c6 = 7) AND (r1c7 = 1) AND (r3c4 = 4) AND (r3c5 = 3) AND (r3c6 = 1) AND (r4c6 = 4) AND (r5c5 = 9) AND (r5c7 = 7) AND (r6c1 = 6) AND (r6c5 = 2) AND (r6c6 = 3) AND (r7c2 = 7) AND (r7c6 = 8) AND (r7c7 = 3) AND (r7c9 = 9) AND (r8c1 = 1) AND (r8c3 = 3) AND (r8c5 = 7) AND (r8c6 = 2) AND (r8c7 = 8) AND (r8c9 = 4) AND (r9c2 = 8) AND (r9c3 = 4) AND (r9c7 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 7) AND (r1c3 = 5) AND (r1c7 = 8) AND (r1c8 = 2) AND (r2c1 = 2) AND (r2c2 = 9) AND (r2c3 = 8) AND (r2c4 = 7) AND (r3c1 = 4) AND (r3c2 = 3) AND (r3c8 = 5) AND (r3c9 = 9) AND (r4c1 = 8) AND (r4c4 = 3) AND (r4c5 = 4) AND (r4c6 = 6) AND (r5c4 = 2) AND (r5c7 = 3) AND (r6c5 = 5) AND (r6c6 = 7) AND (r7c5 = 6) AND (r7c6 = 4) AND (r8c4 = 8) AND (r8c6 = 9) AND (r8c8 = 4) AND (r9c4 = 5) AND (r9c5 = 3) AND (r9c7 = 6) AND (r9c8 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 1) AND (r1c8 = 8) AND (r2c8 = 6) AND (r3c3 = 8) AND (r3c4 = 4) AND (r3c7 = 1) AND (r4c1 = 5) AND (r4c3 = 6) AND (r4c7 = 4) AND (r5c5 = 9) AND (r5c8 = 5) AND (r5c9 = 7) AND (r6c5 = 8) AND (r6c6 = 4) AND (r7c4 = 8) AND (r7c6 = 7) AND (r7c7 = 2) AND (r8c2 = 2) AND (r8c3 = 7) AND (r8c5 = 1) AND (r9c2 = 5) AND (r9c4 = 6) AND (r9c6 = 2) AND (r9c7 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 6) AND (r1c4 = 3) AND (r1c6 = 1) AND (r2c5 = 8) AND (r2c9 = 1) AND (r3c2 = 8) AND (r3c4 = 9) AND (r3c5 = 5) AND (r3c6 = 7) AND (r3c8 = 3) AND (r4c1 = 9) AND (r4c3 = 8) AND (r4c5 = 3) AND (r4c6 = 4) AND (r4c8 = 6) AND (r5c6 = 9) AND (r6c4 = 1) AND (r6c5 = 7) AND (r6c6 = 8) AND (r6c8 = 9) AND (r6c9 = 5) AND (r7c1 = 8) AND (r7c2 = 6) AND (r7c6 = 5) AND (r7c7 = 7) AND (r7c8 = 1) AND (r8c1 = 7) AND (r8c3 = 1) AND (r8c6 = 3) AND (r8c7 = 5) AND (r8c9 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c8 = 4) AND (r2c1 = 6) AND (r2c4 = 3) AND (r2c5 = 8) AND (r2c9 = 7) AND (r3c4 = 7) AND (r3c5 = 9) AND (r3c6 = 6) AND (r4c4 = 6) AND (r4c8 = 3) AND (r5c5 = 1) AND (r6c3 = 7) AND (r6c4 = 4) AND (r6c9 = 2) AND (r7c2 = 4) AND (r7c4 = 8) AND (r7c9 = 6) AND (r8c1 = 3) AND (r8c2 = 1) AND (r9c2 = 9) AND (r9c7 = 2) AND (r9c8 = 1) AND (r9c9 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 1) AND (r1c7 = 6) AND (r2c2 = 4) AND (r2c3 = 3) AND (r2c8 = 8) AND (r2c9 = 5) AND (r3c1 = 6) AND (r3c4 = 5) AND (r3c9 = 2) AND (r4c6 = 3) AND (r4c7 = 2) AND (r5c3 = 5) AND (r5c5 = 1) AND (r5c6 = 7) AND (r5c8 = 6) AND (r5c9 = 8) AND (r6c4 = 8) AND (r6c6 = 5) AND (r6c9 = 1) AND (r7c3 = 2) AND (r7c6 = 6) AND (r7c7 = 1) AND (r7c8 = 3) AND (r7c9 = 4) AND (r8c1 = 4) AND (r8c6 = 1) AND (r8c8 = 2) AND (r8c9 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 4) AND (r1c5 = 2) AND (r1c6 = 9) AND (r1c7 = 3) AND (r1c8 = 6) AND (r2c1 = 3) AND (r2c2 = 8) AND (r2c4 = 1) AND (r2c5 = 4) AND (r2c8 = 2) AND (r3c2 = 9) AND (r4c2 = 1) AND (r4c3 = 9) AND (r4c4 = 8) AND (r4c7 = 4) AND (r5c4 = 4) AND (r5c5 = 9) AND (r5c9 = 7) AND (r6c6 = 3) AND (r7c1 = 8) AND (r7c3 = 6) AND (r8c3 = 7) AND (r8c7 = 8) AND (r9c6 = 2) AND (r9c8 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 1) AND (r1c8 = 6) AND (r2c1 = 6) AND (r2c5 = 7) AND (r2c6 = 2) AND (r3c9 = 9) AND (r4c1 = 1) AND (r4c2 = 8) AND (r4c4 = 2) AND (r4c7 = 5) AND (r6c6 = 5) AND (r6c8 = 9) AND (r6c9 = 4) AND (r7c1 = 7) AND (r7c2 = 5) AND (r7c7 = 9) AND (r8c1 = 4) AND (r8c6 = 6) AND (r8c7 = 8) AND (r8c8 = 5) AND (r9c3 = 6) AND (r9c5 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 6) AND (r1c6 = 7) AND (r1c7 = 5) AND (r2c5 = 5) AND (r2c8 = 6) AND (r2c9 = 4) AND (r3c2 = 5) AND (r3c5 = 6) AND (r3c7 = 9) AND (r3c8 = 8) AND (r3c9 = 1) AND (r4c1 = 1) AND (r5c3 = 7) AND (r5c4 = 9) AND (r5c9 = 2) AND (r6c2 = 9) AND (r6c7 = 1) AND (r7c3 = 4) AND (r7c5 = 1) AND (r7c6 = 5) AND (r7c9 = 9) AND (r8c1 = 8) AND (r8c5 = 7) AND (r8c9 = 6) AND (r9c6 = 2) AND (r9c8 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 9) AND (r1c5 = 6) AND (r2c2 = 2) AND (r2c3 = 7) AND (r2c5 = 9) AND (r2c6 = 1) AND (r2c9 = 5) AND (r3c3 = 3) AND (r3c4 = 7) AND (r3c6 = 8) AND (r4c8 = 3) AND (r5c1 = 5) AND (r5c3 = 6) AND (r5c5 = 2) AND (r5c6 = 9) AND (r5c7 = 7) AND (r6c1 = 2) AND (r6c3 = 1) AND (r6c6 = 7) AND (r7c1 = 3) AND (r7c3 = 9) AND (r7c6 = 6) AND (r7c7 = 1) AND (r7c8 = 2) AND (r8c2 = 6) AND (r8c3 = 5) AND (r8c5 = 1) AND (r8c6 = 2) AND (r9c1 = 1) AND (r9c4 = 9) AND (r9c5 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 3) AND (r1c7 = 7) AND (r1c8 = 6) AND (r2c1 = 8) AND (r2c5 = 2) AND (r2c6 = 6) AND (r2c8 = 5) AND (r3c1 = 4) AND (r3c2 = 5) AND (r4c8 = 1) AND (r5c3 = 2) AND (r5c4 = 8) AND (r5c6 = 5) AND (r5c8 = 3) AND (r5c9 = 7) AND (r6c9 = 8) AND (r7c1 = 2) AND (r7c3 = 8) AND (r7c4 = 6) AND (r8c2 = 3) AND (r8c4 = 5) AND (r8c7 = 6) AND (r8c8 = 2) AND (r9c3 = 7) AND (r9c6 = 2) AND (r9c9 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 9) AND (r2c2 = 1) AND (r2c5 = 8) AND (r2c6 = 6) AND (r2c7 = 4) AND (r3c2 = 4) AND (r4c3 = 8) AND (r4c7 = 1) AND (r4c8 = 3) AND (r5c1 = 5) AND (r5c2 = 3) AND (r6c2 = 7) AND (r6c3 = 1) AND (r6c5 = 3) AND (r6c7 = 5) AND (r7c3 = 7) AND (r7c4 = 4) AND (r7c8 = 1) AND (r8c2 = 5) AND (r8c3 = 4) AND (r8c4 = 7) AND (r8c5 = 9) AND (r8c7 = 6) AND (r8c9 = 8) AND (r9c2 = 6) AND (r9c3 = 9) AND (r9c4 = 8) AND (r9c5 = 5) AND (r9c6 = 1) AND (r9c7 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 7) AND (r1c3 = 8) AND (r1c5 = 2) AND (r2c8 = 9) AND (r2c9 = 1) AND (r3c1 = 3) AND (r4c2 = 4) AND (r4c3 = 6) AND (r5c5 = 3) AND (r5c7 = 7) AND (r6c4 = 5) AND (r7c2 = 5) AND (r7c4 = 9) AND (r7c6 = 6) AND (r8c4 = 4) AND (r8c8 = 1) AND (r9c1 = 2) AND (r9c7 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c7 = 3) AND (r1c9 = 2) AND (r2c3 = 8) AND (r3c5 = 5) AND (r4c9 = 4) AND (r5c2 = 5) AND (r5c5 = 7) AND (r5c8 = 2) AND (r6c2 = 7) AND (r6c4 = 3) AND (r6c5 = 8) AND (r6c6 = 4) AND (r6c8 = 5) AND (r7c2 = 9) AND (r7c3 = 7) AND (r7c6 = 8) AND (r7c9 = 5) AND (r8c2 = 8) AND (r8c3 = 2) AND (r8c5 = 1) AND (r8c6 = 7) AND (r8c8 = 4) AND (r9c2 = 1) AND (r9c3 = 5) AND (r9c4 = 4) AND (r9c5 = 2) AND (r9c9 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 7) AND (r1c6 = 5) AND (r2c1 = 6) AND (r2c9 = 4) AND (r3c1 = 8) AND (r3c2 = 5) AND (r3c6 = 7) AND (r4c6 = 8) AND (r4c9 = 6) AND (r5c1 = 9) AND (r5c2 = 6) AND (r5c5 = 4) AND (r5c7 = 5) AND (r6c3 = 1) AND (r6c6 = 3) AND (r6c7 = 8) AND (r7c3 = 4) AND (r7c5 = 7) AND (r8c1 = 3) AND (r8c4 = 8) AND (r8c7 = 9) AND (r8c9 = 7) AND (r9c2 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 8) AND (r1c5 = 7) AND (r1c8 = 2) AND (r2c7 = 6) AND (r2c9 = 4) AND (r3c3 = 6) AND (r3c4 = 9) AND (r3c6 = 5) AND (r3c7 = 3) AND (r4c4 = 5) AND (r4c6 = 7) AND (r5c5 = 9) AND (r5c8 = 8) AND (r5c9 = 2) AND (r6c7 = 5) AND (r7c1 = 2) AND (r7c2 = 3) AND (r7c6 = 4) AND (r7c9 = 9) AND (r8c1 = 4) AND (r8c4 = 7) AND (r8c5 = 6) AND (r8c9 = 5) AND (r9c1 = 5) AND (r9c5 = 3) AND (r9c6 = 9) AND (r9c8 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 6) AND (r1c4 = 8) AND (r1c6 = 9) AND (r1c9 = 5) AND (r2c1 = 5) AND (r2c6 = 4) AND (r3c1 = 9) AND (r3c2 = 2) AND (r3c7 = 6) AND (r4c3 = 1) AND (r4c7 = 3) AND (r5c3 = 3) AND (r5c5 = 8) AND (r5c9 = 6) AND (r6c1 = 6) AND (r6c4 = 1) AND (r6c5 = 9) AND (r6c8 = 5) AND (r6c9 = 8) AND (r7c9 = 3) AND (r8c6 = 2) AND (r9c4 = 6) AND (r9c7 = 1) AND (r9c9 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c7 = 6) AND (r1c9 = 7) AND (r2c4 = 7) AND (r2c5 = 9) AND (r2c8 = 8) AND (r2c9 = 3) AND (r3c5 = 8) AND (r3c7 = 5) AND (r3c8 = 4) AND (r4c2 = 4) AND (r4c3 = 3) AND (r4c5 = 1) AND (r4c9 = 5) AND (r5c3 = 5) AND (r5c8 = 6) AND (r6c2 = 6) AND (r6c5 = 3) AND (r6c7 = 4) AND (r7c1 = 6) AND (r7c4 = 3) AND (r7c6 = 9) AND (r7c7 = 8) AND (r8c6 = 5) AND (r8c8 = 9) AND (r9c1 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c6 = 2) AND (r2c2 = 4) AND (r2c6 = 6) AND (r2c8 = 7) AND (r2c9 = 1) AND (r3c3 = 9) AND (r3c4 = 3) AND (r3c7 = 4) AND (r4c4 = 9) AND (r4c5 = 4) AND (r5c3 = 6) AND (r5c6 = 1) AND (r5c9 = 7) AND (r6c3 = 1) AND (r6c5 = 2) AND (r6c6 = 7) AND (r7c1 = 7) AND (r7c3 = 4) AND (r7c4 = 1) AND (r7c5 = 6) AND (r7c8 = 9) AND (r7c9 = 5) AND (r8c1 = 9) AND (r9c1 = 6) AND (r9c2 = 1) AND (r9c5 = 5) AND (r9c8 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 7) AND (r1c6 = 1) AND (r1c8 = 4) AND (r2c1 = 8) AND (r2c3 = 9) AND (r2c4 = 2) AND (r2c8 = 1) AND (r3c4 = 8) AND (r3c6 = 7) AND (r3c7 = 2) AND (r3c9 = 5) AND (r4c1 = 5) AND (r5c3 = 4) AND (r5c4 = 6) AND (r5c8 = 8) AND (r6c3 = 7) AND (r6c4 = 4) AND (r7c4 = 9) AND (r7c8 = 6) AND (r7c9 = 8) AND (r8c1 = 9) AND (r8c3 = 5) AND (r8c4 = 1) AND (r8c6 = 8) AND (r8c7 = 4) AND (r8c8 = 7) AND (r9c1 = 4) AND (r9c3 = 8) AND (r9c5 = 2) AND (r9c8 = 5) AND (r9c9 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 7) AND (r1c3 = 8) AND (r1c9 = 4) AND (r2c1 = 6) AND (r2c3 = 2) AND (r2c7 = 5) AND (r2c8 = 8) AND (r3c1 = 5) AND (r3c2 = 4) AND (r3c5 = 2) AND (r3c7 = 1) AND (r3c8 = 6) AND (r3c9 = 7) AND (r4c7 = 8) AND (r4c8 = 4) AND (r5c1 = 2) AND (r5c7 = 7) AND (r5c9 = 5) AND (r6c1 = 4) AND (r6c2 = 8) AND (r6c3 = 5) AND (r6c6 = 1) AND (r6c8 = 2) AND (r7c1 = 7) AND (r7c4 = 3) AND (r7c6 = 4) AND (r8c9 = 2) AND (r9c1 = 8) AND (r9c2 = 5) AND (r9c6 = 6) AND (r9c7 = 4) AND (r9c8 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 5) AND (r1c9 = 3) AND (r2c3 = 6) AND (r2c6 = 1) AND (r2c8 = 8) AND (r3c4 = 4) AND (r3c7 = 6) AND (r3c9 = 2) AND (r4c9 = 1) AND (r5c4 = 9) AND (r5c6 = 8) AND (r5c7 = 5) AND (r6c5 = 3) AND (r6c6 = 6) AND (r6c7 = 8) AND (r7c1 = 4) AND (r7c7 = 1) AND (r7c8 = 9) AND (r8c1 = 8) AND (r8c3 = 5) AND (r8c5 = 1) AND (r8c8 = 4) AND (r9c4 = 6) AND (r9c6 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 9) AND (r1c5 = 3) AND (r2c3 = 6) AND (r2c4 = 2) AND (r2c6 = 8) AND (r3c4 = 9) AND (r3c5 = 7) AND (r3c9 = 5) AND (r5c1 = 2) AND (r5c3 = 9) AND (r5c4 = 8) AND (r5c6 = 3) AND (r6c4 = 6) AND (r6c6 = 7) AND (r6c9 = 9) AND (r7c1 = 7) AND (r7c2 = 5) AND (r7c8 = 8) AND (r7c9 = 4) AND (r8c2 = 4) AND (r8c3 = 8) AND (r8c5 = 5) AND (r8c7 = 6) AND (r8c9 = 3) AND (r9c3 = 2) AND (r9c8 = 5) AND (r9c9 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 1) AND (r1c5 = 2) AND (r2c4 = 1) AND (r2c9 = 8) AND (r3c2 = 8) AND (r3c4 = 3) AND (r3c6 = 7) AND (r3c8 = 1) AND (r4c2 = 5) AND (r4c3 = 7) AND (r4c8 = 3) AND (r5c3 = 2) AND (r5c7 = 6) AND (r6c1 = 8) AND (r6c7 = 5) AND (r6c8 = 7) AND (r6c9 = 4) AND (r7c2 = 7) AND (r7c9 = 3) AND (r8c3 = 4) AND (r8c4 = 7) AND (r8c7 = 1) AND (r8c8 = 2) AND (r9c1 = 2) AND (r9c3 = 5) AND (r9c7 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 8) AND (r1c2 = 1) AND (r1c6 = 3) AND (r1c7 = 9) AND (r2c2 = 6) AND (r2c8 = 8) AND (r2c9 = 2) AND (r3c1 = 2) AND (r3c4 = 7) AND (r3c7 = 3) AND (r4c2 = 8) AND (r4c5 = 3) AND (r4c6 = 6) AND (r5c2 = 9) AND (r5c5 = 1) AND (r5c7 = 4) AND (r5c8 = 3) AND (r6c3 = 6) AND (r6c6 = 9) AND (r7c3 = 2) AND (r8c5 = 8) AND (r8c8 = 7) AND (r9c9 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 7) AND (r1c5 = 8) AND (r1c7 = 4) AND (r2c1 = 3) AND (r2c9 = 2) AND (r4c1 = 1) AND (r4c3 = 6) AND (r4c4 = 3) AND (r5c7 = 8) AND (r5c8 = 5) AND (r6c1 = 2) AND (r7c2 = 8) AND (r7c3 = 4) AND (r7c8 = 3) AND (r8c4 = 2) AND (r8c6 = 1) AND (r9c5 = 5);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 4) AND (r1c3 = 9) AND (r2c6 = 7) AND (r3c2 = 6) AND (r3c7 = 4) AND (r4c1 = 9) AND (r4c2 = 1) AND (r4c4 = 7) AND (r4c8 = 3) AND (r4c9 = 6) AND (r5c4 = 3) AND (r5c5 = 5) AND (r5c7 = 1) AND (r5c8 = 4) AND (r6c1 = 2) AND (r7c4 = 5) AND (r7c8 = 7) AND (r8c2 = 3) AND (r8c3 = 6) AND (r8c5 = 2) AND (r9c2 = 2) AND (r9c4 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c5 = 5) AND (r1c8 = 4) AND (r1c9 = 6) AND (r2c6 = 1) AND (r2c8 = 7) AND (r3c1 = 3) AND (r3c3 = 6) AND (r3c6 = 9) AND (r3c7 = 5) AND (r3c9 = 1) AND (r4c2 = 5) AND (r4c5 = 9) AND (r4c6 = 4) AND (r5c4 = 2) AND (r6c1 = 9) AND (r6c5 = 7) AND (r6c9 = 3) AND (r7c1 = 4) AND (r7c5 = 6) AND (r7c6 = 7) AND (r7c8 = 2) AND (r7c9 = 5) AND (r9c1 = 6) AND (r9c4 = 5) AND (r9c5 = 1) AND (r9c6 = 3) AND (r9c9 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 7) AND (r1c4 = 2) AND (r1c6 = 4) AND (r1c8 = 1) AND (r2c1 = 4) AND (r2c2 = 9) AND (r2c4 = 1) AND (r2c6 = 7) AND (r2c8 = 5) AND (r2c9 = 2) AND (r3c5 = 5) AND (r4c1 = 1) AND (r4c2 = 3) AND (r4c8 = 9) AND (r4c9 = 7) AND (r5c3 = 9) AND (r5c7 = 2) AND (r6c1 = 5) AND (r6c2 = 4) AND (r6c8 = 6) AND (r6c9 = 3) AND (r7c5 = 2) AND (r8c1 = 2) AND (r8c2 = 5) AND (r8c4 = 7) AND (r8c6 = 1) AND (r8c8 = 8) AND (r8c9 = 6) AND (r9c2 = 1) AND (r9c4 = 6) AND (r9c6 = 3) AND (r9c8 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 5) AND (r1c6 = 2) AND (r1c9 = 4) AND (r2c1 = 7) AND (r2c3 = 2) AND (r2c6 = 4) AND (r2c7 = 3) AND (r2c8 = 5) AND (r3c2 = 1) AND (r3c6 = 3) AND (r3c7 = 9) AND (r4c1 = 3) AND (r4c3 = 7) AND (r4c4 = 5) AND (r4c6 = 8) AND (r4c7 = 2) AND (r6c7 = 7) AND (r6c9 = 8) AND (r7c2 = 7) AND (r7c3 = 1) AND (r7c5 = 8) AND (r7c6 = 5) AND (r7c7 = 4) AND (r8c1 = 4) AND (r8c3 = 3) AND (r8c9 = 2) AND (r9c1 = 2) AND (r9c3 = 8) AND (r9c5 = 3) AND (r9c9 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 8) AND (r1c8 = 1) AND (r2c6 = 2) AND (r2c8 = 3) AND (r2c9 = 4) AND (r3c3 = 2) AND (r3c5 = 5) AND (r4c4 = 4) AND (r4c8 = 6) AND (r5c3 = 7) AND (r5c7 = 8) AND (r6c2 = 5) AND (r7c5 = 7) AND (r7c7 = 5) AND (r8c1 = 9) AND (r8c2 = 4) AND (r8c4 = 1) AND (r9c2 = 6) AND (r9c9 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c9 = 1) AND (r2c6 = 4) AND (r2c8 = 8) AND (r3c2 = 4) AND (r3c4 = 6) AND (r3c6 = 1) AND (r3c8 = 2) AND (r4c1 = 5) AND (r4c2 = 6) AND (r4c3 = 2) AND (r4c5 = 7) AND (r4c7 = 3) AND (r4c8 = 4) AND (r5c1 = 1) AND (r5c3 = 7) AND (r5c6 = 3) AND (r5c9 = 2) AND (r6c1 = 4) AND (r6c2 = 3) AND (r6c5 = 6) AND (r6c8 = 7) AND (r7c9 = 7) AND (r8c6 = 6) AND (r8c7 = 8) AND (r8c9 = 4) AND (r9c1 = 3) AND (r9c4 = 8) AND (r9c6 = 7) AND (r9c7 = 2) AND (r9c8 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c6 = 3) AND (r2c1 = 7) AND (r2c7 = 8) AND (r2c8 = 5) AND (r3c2 = 8) AND (r3c4 = 4) AND (r3c5 = 9) AND (r3c8 = 7) AND (r4c3 = 4) AND (r5c2 = 3) AND (r5c4 = 1) AND (r5c5 = 8) AND (r6c1 = 6) AND (r6c3 = 9) AND (r6c9 = 4) AND (r8c3 = 6) AND (r8c5 = 5) AND (r8c9 = 3) AND (r9c5 = 6) AND (r9c9 = 1);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 9) AND (r1c6 = 4) AND (r1c8 = 8) AND (r1c9 = 6) AND (r2c3 = 6) AND (r2c4 = 3) AND (r2c7 = 7) AND (r3c2 = 4) AND (r3c3 = 8) AND (r3c8 = 3) AND (r3c9 = 5) AND (r4c2 = 9) AND (r4c4 = 4) AND (r5c3 = 1) AND (r6c1 = 4) AND (r6c3 = 5) AND (r6c4 = 9) AND (r6c6 = 6) AND (r7c1 = 7) AND (r7c2 = 8) AND (r7c3 = 4) AND (r7c5 = 6) AND (r7c6 = 9) AND (r7c9 = 3) AND (r8c6 = 3) AND (r9c1 = 6) AND (r9c4 = 1) AND (r9c5 = 4) AND (r9c6 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 5) AND (r1c4 = 9) AND (r1c7 = 1) AND (r2c4 = 4) AND (r2c7 = 9) AND (r3c1 = 6) AND (r3c2 = 3) AND (r3c5 = 2) AND (r3c7 = 5) AND (r4c1 = 4) AND (r4c9 = 6) AND (r5c3 = 1) AND (r5c5 = 3) AND (r6c8 = 3) AND (r6c9 = 4) AND (r7c1 = 7) AND (r7c2 = 2) AND (r7c4 = 6) AND (r8c4 = 7) AND (r9c8 = 5);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 2) AND (r1c5 = 1) AND (r1c7 = 4) AND (r2c3 = 3) AND (r2c5 = 9) AND (r2c7 = 2) AND (r2c8 = 5) AND (r3c1 = 7) AND (r3c3 = 5) AND (r4c4 = 9) AND (r4c7 = 6) AND (r4c9 = 3) AND (r5c1 = 9) AND (r6c3 = 2) AND (r6c6 = 5) AND (r7c5 = 2) AND (r7c8 = 4) AND (r8c6 = 9) AND (r8c8 = 2) AND (r8c9 = 7) AND (r9c3 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 3) AND (r1c6 = 5) AND (r2c1 = 4) AND (r2c4 = 8) AND (r2c5 = 6) AND (r2c6 = 9) AND (r2c9 = 5) AND (r3c1 = 8) AND (r4c3 = 9) AND (r4c6 = 2) AND (r4c8 = 5) AND (r4c9 = 6) AND (r5c1 = 1) AND (r5c3 = 2) AND (r5c8 = 3) AND (r6c1 = 6) AND (r6c2 = 8) AND (r6c4 = 9) AND (r6c5 = 3) AND (r6c8 = 2) AND (r6c9 = 4) AND (r7c2 = 3) AND (r7c3 = 8) AND (r7c4 = 6) AND (r7c9 = 9) AND (r8c1 = 5) AND (r9c3 = 6) AND (r9c9 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 7) AND (r1c9 = 1) AND (r2c3 = 2) AND (r2c4 = 9) AND (r2c8 = 5) AND (r3c1 = 8) AND (r3c7 = 4) AND (r4c3 = 6) AND (r4c4 = 2) AND (r4c5 = 5) AND (r5c6 = 7) AND (r6c4 = 3) AND (r6c6 = 6) AND (r6c8 = 9) AND (r7c1 = 4) AND (r7c7 = 7) AND (r8c2 = 1) AND (r8c9 = 8) AND (r9c3 = 5) AND (r9c5 = 3) AND (r9c8 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 3) AND (r1c4 = 5) AND (r1c8 = 8) AND (r2c1 = 7) AND (r2c5 = 2) AND (r3c3 = 9) AND (r3c6 = 7) AND (r4c4 = 2) AND (r4c6 = 1) AND (r5c1 = 5) AND (r5c2 = 2) AND (r6c2 = 4) AND (r6c5 = 8) AND (r6c7 = 7) AND (r7c4 = 3) AND (r7c8 = 2) AND (r8c5 = 9) AND (r8c6 = 8) AND (r8c7 = 3) AND (r9c2 = 1) AND (r9c3 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 8) AND (r1c2 = 1) AND (r1c3 = 2) AND (r1c5 = 3) AND (r2c1 = 4) AND (r2c7 = 5) AND (r3c4 = 7) AND (r3c7 = 2) AND (r3c8 = 3) AND (r4c1 = 2) AND (r4c4 = 8) AND (r4c5 = 5) AND (r5c1 = 3) AND (r5c4 = 1) AND (r5c5 = 6) AND (r5c6 = 7) AND (r5c7 = 8) AND (r5c9 = 5) AND (r6c4 = 4) AND (r6c8 = 7) AND (r6c9 = 6) AND (r7c1 = 1) AND (r7c5 = 7) AND (r8c2 = 6) AND (r8c3 = 5) AND (r8c9 = 8) AND (r9c9 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c7 = 8) AND (r2c1 = 2) AND (r2c2 = 8) AND (r2c3 = 3) AND (r2c7 = 4) AND (r2c8 = 1) AND (r3c4 = 2) AND (r4c3 = 1) AND (r4c4 = 3) AND (r4c9 = 6) AND (r5c3 = 2) AND (r5c4 = 1) AND (r5c6 = 6) AND (r5c8 = 5) AND (r5c9 = 4) AND (r6c6 = 5) AND (r6c8 = 7) AND (r7c1 = 1) AND (r7c3 = 5) AND (r8c4 = 4) AND (r8c8 = 3) AND (r8c9 = 1) AND (r9c1 = 3) AND (r9c3 = 8) AND (r9c6 = 1) AND (r9c7 = 6) AND (r9c8 = 2) AND (r9c9 = 5);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c6 = 5) AND (r1c9 = 1) AND (r2c2 = 6) AND (r2c5 = 7) AND (r2c7 = 2) AND (r3c2 = 1) AND (r3c3 = 7) AND (r4c3 = 3) AND (r4c4 = 5) AND (r4c5 = 2) AND (r5c4 = 8) AND (r5c5 = 3) AND (r5c7 = 1) AND (r5c9 = 4) AND (r7c4 = 7) AND (r7c9 = 5) AND (r8c3 = 2) AND (r8c6 = 1) AND (r8c9 = 3) AND (r9c1 = 3) AND (r9c2 = 4) AND (r9c9 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 7) AND (r1c4 = 5) AND (r1c6 = 8) AND (r1c8 = 6) AND (r2c1 = 8) AND (r2c5 = 1) AND (r2c9 = 7) AND (r3c2 = 9) AND (r3c8 = 8) AND (r4c3 = 8) AND (r4c4 = 6) AND (r4c6 = 9) AND (r4c7 = 7) AND (r5c2 = 5) AND (r5c3 = 9) AND (r5c4 = 2) AND (r5c6 = 7) AND (r5c7 = 8) AND (r5c8 = 1) AND (r6c3 = 7) AND (r6c4 = 1) AND (r6c6 = 3) AND (r6c7 = 5) AND (r7c2 = 3) AND (r7c8 = 4) AND (r8c1 = 7) AND (r8c5 = 6) AND (r8c9 = 2) AND (r9c2 = 6) AND (r9c4 = 8) AND (r9c6 = 4) AND (r9c8 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 8) AND (r1c7 = 7) AND (r1c8 = 4) AND (r2c1 = 5) AND (r2c3 = 1) AND (r3c1 = 3) AND (r3c8 = 9) AND (r4c2 = 9) AND (r4c4 = 2) AND (r4c7 = 5) AND (r5c4 = 6) AND (r5c5 = 8) AND (r6c7 = 3) AND (r7c5 = 3) AND (r7c6 = 1) AND (r8c2 = 2) AND (r8c9 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 3) AND (r1c7 = 5) AND (r1c9 = 9) AND (r2c1 = 9) AND (r2c2 = 8) AND (r2c3 = 6) AND (r2c5 = 2) AND (r2c7 = 3) AND (r3c3 = 2) AND (r3c9 = 1) AND (r4c7 = 1) AND (r4c8 = 7) AND (r5c4 = 5) AND (r5c6 = 7) AND (r7c1 = 7) AND (r7c6 = 3) AND (r7c7 = 8) AND (r7c8 = 6) AND (r8c3 = 8) AND (r8c4 = 2) AND (r8c5 = 6) AND (r9c2 = 5) AND (r9c9 = 3);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 4) AND (r1c9 = 3) AND (r2c2 = 2) AND (r2c5 = 5) AND (r2c9 = 9) AND (r3c2 = 9) AND (r3c3 = 5) AND (r3c5 = 3) AND (r3c8 = 8) AND (r4c4 = 4) AND (r6c1 = 6) AND (r6c6 = 9) AND (r6c7 = 7) AND (r7c1 = 4) AND (r7c4 = 7) AND (r7c7 = 6) AND (r7c8 = 2) AND (r8c4 = 6) AND (r8c9 = 5) AND (r9c1 = 3) AND (r9c4 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 9) AND (r2c5 = 6) AND (r2c8 = 1) AND (r3c6 = 5) AND (r4c2 = 1) AND (r4c6 = 9) AND (r5c1 = 8) AND (r5c5 = 4) AND (r6c1 = 4) AND (r6c2 = 2) AND (r6c4 = 8) AND (r6c8 = 3) AND (r7c4 = 9) AND (r7c7 = 5) AND (r7c9 = 3) AND (r8c2 = 8) AND (r8c3 = 5) AND (r8c4 = 3) AND (r8c9 = 1) AND (r9c4 = 1) AND (r9c6 = 2) AND (r9c8 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c8 = 1) AND (r2c1 = 3) AND (r2c2 = 2) AND (r2c4 = 9) AND (r2c9 = 5) AND (r3c2 = 8) AND (r3c4 = 4) AND (r3c5 = 5) AND (r4c3 = 2) AND (r4c4 = 5) AND (r4c6 = 3) AND (r5c8 = 5) AND (r5c9 = 9) AND (r6c1 = 7) AND (r6c9 = 3) AND (r7c3 = 7) AND (r8c1 = 5) AND (r8c5 = 4) AND (r8c7 = 1) AND (r9c2 = 9) AND (r9c3 = 1) AND (r9c4 = 3) AND (r9c7 = 5) AND (r9c8 = 2) AND (r9c9 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 8) AND (r1c4 = 5) AND (r1c8 = 4) AND (r2c1 = 5) AND (r2c4 = 3) AND (r2c6 = 8) AND (r3c1 = 2) AND (r3c7 = 9) AND (r4c2 = 6) AND (r4c5 = 7) AND (r5c1 = 4) AND (r5c2 = 3) AND (r5c7 = 6) AND (r6c3 = 5) AND (r6c5 = 8) AND (r7c3 = 9) AND (r7c9 = 6) AND (r8c1 = 7) AND (r8c7 = 5) AND (r9c2 = 8) AND (r9c4 = 4) AND (r9c6 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 9) AND (r1c4 = 3) AND (r1c6 = 5) AND (r1c7 = 7) AND (r2c2 = 3) AND (r2c4 = 8) AND (r2c9 = 2) AND (r3c3 = 8) AND (r3c5 = 2) AND (r3c7 = 6) AND (r4c3 = 2) AND (r4c8 = 9) AND (r4c9 = 7) AND (r5c2 = 7) AND (r5c3 = 6) AND (r5c5 = 5) AND (r5c7 = 1) AND (r6c2 = 8) AND (r6c7 = 3) AND (r7c4 = 9) AND (r7c9 = 1) AND (r8c6 = 1) AND (r9c8 = 6);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 1) AND (r1c6 = 6) AND (r1c9 = 7) AND (r2c2 = 2) AND (r2c4 = 5) AND (r2c7 = 8) AND (r3c3 = 9) AND (r3c4 = 7) AND (r3c9 = 6) AND (r4c1 = 7) AND (r4c3 = 5) AND (r5c3 = 1) AND (r5c5 = 3) AND (r5c7 = 2) AND (r5c8 = 9) AND (r7c5 = 9) AND (r7c6 = 5) AND (r8c1 = 2) AND (r8c9 = 3) AND (r9c1 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 2) AND (r1c2 = 9) AND (r1c4 = 1) AND (r1c5 = 4) AND (r2c5 = 5) AND (r2c6 = 8) AND (r3c1 = 1) AND (r3c2 = 8) AND (r3c5 = 6) AND (r3c7 = 5) AND (r4c1 = 8) AND (r4c9 = 2) AND (r5c2 = 1) AND (r5c4 = 7) AND (r5c9 = 6) AND (r6c7 = 7) AND (r6c8 = 9) AND (r7c1 = 4) AND (r7c7 = 2) AND (r7c8 = 1) AND (r8c9 = 9) AND (r9c1 = 7) AND (r9c4 = 2) AND (r9c7 = 4) AND (r9c9 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 6) AND (r1c3 = 1) AND (r1c5 = 9) AND (r3c1 = 9) AND (r3c3 = 7) AND (r3c5 = 4) AND (r3c8 = 6) AND (r4c3 = 8) AND (r4c8 = 4) AND (r5c1 = 7) AND (r5c2 = 3) AND (r5c3 = 2) AND (r5c8 = 9) AND (r6c1 = 1) AND (r6c8 = 7) AND (r7c2 = 8) AND (r7c3 = 4) AND (r7c4 = 6) AND (r7c5 = 1) AND (r7c9 = 9) AND (r8c1 = 2) AND (r8c3 = 9) AND (r8c5 = 8) AND (r8c6 = 4) AND (r8c7 = 3) AND (r9c5 = 2) AND (r9c6 = 7) AND (r9c8 = 8) AND (r9c9 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 4) AND (r1c6 = 1) AND (r1c8 = 2) AND (r2c8 = 3) AND (r2c9 = 4) AND (r3c3 = 5) AND (r3c5 = 6) AND (r4c4 = 3) AND (r4c9 = 7) AND (r5c3 = 1) AND (r5c7 = 6) AND (r6c1 = 6) AND (r6c6 = 2) AND (r7c5 = 4) AND (r7c7 = 1) AND (r8c1 = 9) AND (r8c2 = 7) AND (r9c2 = 3) AND (r9c4 = 5);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 8) AND (r1c2 = 9) AND (r2c1 = 3) AND (r2c3 = 6) AND (r2c5 = 4) AND (r3c2 = 1) AND (r3c3 = 4) AND (r4c2 = 7) AND (r4c9 = 1) AND (r5c3 = 1) AND (r5c5 = 6) AND (r6c1 = 2) AND (r6c6 = 7) AND (r6c7 = 9) AND (r6c9 = 8) AND (r7c1 = 7) AND (r7c4 = 6) AND (r7c5 = 2) AND (r7c6 = 1) AND (r7c7 = 8) AND (r7c9 = 3) AND (r8c4 = 7) AND (r8c6 = 3) AND (r8c7 = 4) AND (r8c8 = 9) AND (r9c2 = 3) AND (r9c5 = 8) AND (r9c6 = 9) AND (r9c8 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 4) AND (r2c2 = 4) AND (r2c5 = 7) AND (r2c8 = 3) AND (r2c9 = 6) AND (r3c1 = 2) AND (r3c5 = 3) AND (r3c6 = 6) AND (r3c8 = 8) AND (r4c4 = 1) AND (r4c5 = 4) AND (r4c9 = 7) AND (r5c1 = 1) AND (r5c6 = 3) AND (r5c8 = 6) AND (r6c4 = 6) AND (r6c8 = 2) AND (r7c1 = 3) AND (r7c5 = 5) AND (r7c8 = 1) AND (r8c2 = 5) AND (r8c4 = 7) AND (r8c5 = 8) AND (r8c6 = 2) AND (r9c9 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 8) AND (r1c8 = 1) AND (r2c6 = 2) AND (r2c8 = 3) AND (r2c9 = 4) AND (r3c3 = 5) AND (r3c5 = 6) AND (r4c4 = 4) AND (r4c8 = 7) AND (r5c3 = 2) AND (r5c7 = 6) AND (r6c2 = 1) AND (r6c6 = 5) AND (r7c5 = 8) AND (r7c7 = 2) AND (r8c1 = 7) AND (r8c2 = 3) AND (r8c4 = 1) AND (r9c2 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 8) AND (r1c4 = 4) AND (r1c5 = 3) AND (r1c7 = 9) AND (r1c8 = 1) AND (r2c1 = 3) AND (r2c5 = 9) AND (r3c2 = 4) AND (r3c4 = 7) AND (r3c6 = 1) AND (r3c9 = 6) AND (r4c2 = 7) AND (r4c4 = 1) AND (r4c5 = 4) AND (r4c7 = 5) AND (r5c1 = 6) AND (r5c3 = 3) AND (r6c1 = 5) AND (r6c2 = 1) AND (r6c8 = 8) AND (r7c1 = 7) AND (r7c3 = 6) AND (r7c4 = 8) AND (r7c8 = 9) AND (r8c2 = 3) AND (r8c4 = 9) AND (r9c2 = 9) AND (r9c4 = 3) AND (r9c9 = 8);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 7) AND (r1c3 = 1) AND (r1c4 = 2) AND (r1c5 = 5) AND (r1c8 = 8) AND (r2c1 = 8) AND (r2c3 = 6) AND (r2c5 = 7) AND (r2c6 = 4) AND (r2c9 = 5) AND (r3c2 = 9) AND (r3c3 = 4) AND (r3c6 = 6) AND (r3c7 = 7) AND (r5c3 = 8) AND (r5c4 = 6) AND (r5c6 = 5) AND (r5c9 = 9) AND (r6c4 = 8) AND (r6c5 = 2) AND (r6c6 = 1) AND (r6c8 = 4) AND (r6c9 = 6) AND (r7c1 = 6) AND (r7c6 = 8) AND (r7c9 = 1) AND (r8c1 = 1) AND (r8c3 = 9) AND (r8c9 = 7) AND (r9c2 = 4);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 1) AND (r1c5 = 5) AND (r1c7 = 6) AND (r2c1 = 8) AND (r2c3 = 7) AND (r3c1 = 3) AND (r4c4 = 7) AND (r4c6 = 8) AND (r4c8 = 3) AND (r5c2 = 1) AND (r5c7 = 4) AND (r7c2 = 4) AND (r7c5 = 6) AND (r7c7 = 2) AND (r8c1 = 5) AND (r8c8 = 8) AND (r9c4 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 7) AND (r1c5 = 9) AND (r1c7 = 2) AND (r2c3 = 6) AND (r2c7 = 3) AND (r2c9 = 8) AND (r3c2 = 5) AND (r3c5 = 8) AND (r3c6 = 3) AND (r3c8 = 7) AND (r3c9 = 9) AND (r4c3 = 4) AND (r4c4 = 3) AND (r4c7 = 7) AND (r4c8 = 6) AND (r5c7 = 8) AND (r5c9 = 2) AND (r6c1 = 5) AND (r6c2 = 6) AND (r8c2 = 8) AND (r8c3 = 9) AND (r8c4 = 5) AND (r8c6 = 6) AND (r9c1 = 3) AND (r9c2 = 2) AND (r9c9 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c3 = 2) AND (r1c4 = 8) AND (r1c6 = 1) AND (r1c7 = 5) AND (r1c8 = 4) AND (r2c5 = 3) AND (r3c4 = 4) AND (r3c5 = 6) AND (r3c6 = 5) AND (r4c1 = 8) AND (r4c3 = 3) AND (r4c6 = 9) AND (r4c7 = 4) AND (r4c9 = 5) AND (r5c2 = 5) AND (r5c6 = 3) AND (r5c9 = 1) AND (r6c3 = 6) AND (r6c7 = 3) AND (r7c4 = 2) AND (r7c6 = 4) AND (r8c3 = 5) AND (r8c5 = 1) AND (r8c6 = 8) AND (r8c7 = 6) AND (r8c8 = 2) AND (r9c3 = 9) AND (r9c5 = 5);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c4 = 1) AND (r2c1 = 1) AND (r2c2 = 2) AND (r2c5 = 9) AND (r2c8 = 7) AND (r3c5 = 7) AND (r3c6 = 6) AND (r5c2 = 6) AND (r5c5 = 3) AND (r5c6 = 9) AND (r5c8 = 1) AND (r6c1 = 5) AND (r6c3 = 9) AND (r6c4 = 4) AND (r6c6 = 7) AND (r6c8 = 2) AND (r7c3 = 2) AND (r7c6 = 3) AND (r7c7 = 4) AND (r7c8 = 5) AND (r8c1 = 6) AND (r8c4 = 7) AND (r8c5 = 2) AND (r8c8 = 3) AND (r8c9 = 9) AND (r9c2 = 7) AND (r9c4 = 9) AND (r9c5 = 4) AND (r9c6 = 1) AND (r9c8 = 6) AND (r9c9 = 2);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 2) AND (r2c3 = 5) AND (r2c5 = 3) AND (r2c6 = 9) AND (r2c7 = 8) AND (r3c1 = 8) AND (r3c2 = 4) AND (r3c3 = 9) AND (r3c5 = 7) AND (r4c3 = 7) AND (r4c4 = 3) AND (r4c5 = 2) AND (r4c6 = 6) AND (r5c4 = 7) AND (r5c5 = 4) AND (r5c6 = 8) AND (r5c9 = 3) AND (r6c6 = 5) AND (r7c3 = 3) AND (r7c5 = 6) AND (r7c9 = 5) AND (r8c2 = 5) AND (r8c4 = 9) AND (r8c8 = 6) AND (r9c1 = 4) AND (r9c3 = 8) AND (r9c5 = 5) AND (r9c6 = 7) AND (r9c8 = 3) AND (r9c9 = 9);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 1) AND (r1c2 = 9) AND (r2c1 = 8) AND (r2c5 = 7) AND (r2c8 = 1) AND (r2c9 = 6) AND (r3c2 = 7) AND (r3c4 = 2) AND (r3c7 = 5) AND (r3c9 = 3) AND (r4c8 = 2) AND (r4c9 = 7) AND (r5c2 = 3) AND (r5c9 = 8) AND (r6c1 = 9) AND (r6c3 = 5) AND (r7c2 = 1) AND (r7c3 = 8) AND (r7c6 = 2) AND (r7c8 = 3) AND (r8c9 = 2) AND (r9c2 = 6) AND (r9c5 = 1) AND (r9c8 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c1 = 8) AND (r1c3 = 5) AND (r1c9 = 2) AND (r2c4 = 9) AND (r2c6 = 1) AND (r3c1 = 3) AND (r4c2 = 6) AND (r4c4 = 7) AND (r4c7 = 4) AND (r5c1 = 2) AND (r5c5 = 5) AND (r6c8 = 6) AND (r7c4 = 3) AND (r7c5 = 8) AND (r8c2 = 1) AND (r8c7 = 9) AND (r9c2 = 4) AND (r9c8 = 7);
SELECT * FROM sudoku_memory_combined_view WHERE (r1c2 = 8) AND (r2c1 = 1) AND (r2c3 = 7) AND (r2c7 = 8) AND (r2c9 = 3) AND (r3c6 = 6) AND (r3c9 = 1) AND (r4c2 = 2) AND (r5c1 = 3) AND (r5c5 = 1) AND (r6c3 = 8) AND (r6c4 = 5) AND (r6c7 = 6) AND (r6c8 = 9) AND (r7c5 = 3) AND (r7c6 = 7) AND (r7c7 = 9) AND (r8c6 = 1) AND (r9c1 = 5) AND (r9c2 = 9);
UPDATE tests SET fin = NOW() WHERE fin IS NULL;
SELECT TO_SECONDS(fin) - TO_SECONDS(debut) FROM tests;

6. Gosser à la main!

Maintenant que nous avons un échantillon représentatif et significatif et tout ce qu’il nous faut pour mesurer, de façon répétable et facile, chacun des changements que nous voulons effectuer, nous sommes en mesure de vérifier l’impact de 2 variables importantes : optimizer_search_depth et join_buffer_size.

Tout d’abord, la variable optimizer_search_depth dont voici les différents résultats :

optimizer_search_depth_table

Il est clair que cette variable a un impact majeur.  Nous savons maintenant que la valeur optimale de cette variable (dans notre cas précis) est 1.

optimizer_search_depth

On serait tenté de croire que la variable join_buffer_size pourrait avoir un impact non négligeable mais ce n’est pas le cas ici.

join_buffer_size_table

Les différences de temps (hormis pour la valeur 2Mb) ne sont pas assez significatives pour indiquer une tendance.  Malgré tout, théoriquement, cette variable devrait avoir un impact.  Pour les biens de la cause, autant avoir plus de mémoire que moins pour cette variable!  Je vous recommande donc 128Mb (plus, dans notre cas, serait un gaspillage de mémoire).

join_buffer_size

Finalement, pour mettre en valeur la différence entre une solution utilisant une table sur disque versus notre solution finale (une table en mémoire), l’histogramme suivant parle de lui-même!

engine_type

Voilà!  CQFD. En espérant que cette série d’articles vous aura permis de constater que parfois, il est nécessaire de penser out of the box et d’envisager des solutions saugrenues pour arriver à ses fins.

7. Ressources et outils

Quelques-unes des ressources et des outils utilisés dans le cadre de cette série d’articles:

setbb.com : des forums de discussion sur le sudoku (en anglais) pour les programmeurs

enjoysudoku.com : des forums de discussions (en anglais) variés et nombreux sur les sudokus

QQWing : un outil (en ligne de commande) permettant de solutionner et de générer des grilles de sudoku

SudoCue : une application permettant de solutionner et générer des sudokus

Sudoku Explainer : une application permettant de solutionner et générer des sudokus

R : langage de programmation et environnement mathématique utilisé pour le traitement de données et l’analyse statistique

db4free.net : un serveur MySQL vous permettant de créer une base de donnée gratuitement et d’expérimenter

Pharo : un environnement de développement Smalltalk


Smalltalk et performance : tinyBenchmarks

8 décembre 2012

Il existe plusieurs programmes d’évaluation (benchmarks) servant à établir des comparaisons.  Le plus simple dont nous disposions en Smalltalk est tinyBenchmark (dans Squeak, Pharo et quelques autres saveurs de Smalltalk).

Ce petit test simpliste mesure le nombre de bytecodes traités par seconde ainsi que le nombre d’envois de messages (message sends) par seconde.  Bref, ce test vaut ce qu’il vaut : il évalue  principalement la rapidité de la machine virtuelle sans se soucier de l’efficacité et de la rapidité du code Smalltalk ou des primitives.

Un test plus représentatif et complet, comme le Computer Language Benchmark Game, est nettement plus révélateur de l’ensemble des capacité d’un environnement Smalltalk.  Dans le passé, il en existait des versions pour Squeak et GNU Smalltalk mais il ne semble maintenant rester que celle de VisualWorks.  Le code Smalltalk pour le CLBG est toutefois disponible ici

Malgré tout, par simple curiosité, j’ai utilisé tinyBenchmark pour comparer différentes versions de Smalltalk.  Les versions évaluées étaient:

  • VisualWorks Non Commercial 7.8 (VW)
  • ObjectStudio 7.1 (OS)
  • VisualSmalltalk 3.0.1 (VS)
  • Squeak 4.2 All-in-One (SQ)
  • PharoCore 1.2 RC3 (PH)
  • VA Smalltalk 7.5 (VAST)
  • Dolphin Professional 6.02 (DP)
  • Amber 0.9.1 (AM)

Sans m’en douter, quelques surprises m’attendaient!

1) Bytecodes par seconde

VisualWorks Non Commercial 7.8 : 607691685
ObjectStudio 7.1 : 35717175
Visual Smalltalk 3.0.1 : 281603053
Squeak 4.2 All-in-One : 85373820
PharoCore 1.2 RC3 : 97390689
VA Smalltalk 7.5 : 358381181
Dolphin Professional 6.02 : 110771676
Amber 0.9.1 : 2195520

Bytecodes par seconde

Bytecodes par seconde

On remarque immédiatement la nette domination de VisualWorks sur tous ses concurrents et la seconde place de VisualAge.  La performance de VisualSmalltalk est surprenant tandis que je m’attendais à ce que Dolphin fasse mieux!  Évidemment, dans le cas d’Amber, il s’agit d’un petit nouveau mais laissons-lui le temps de mûrir un peu!

2) Envois de messages par seconde

VisualWorks Non Commercial 7.8 : 52403197
ObjectStudio 7.1 : 708240
VisualSmalltalk 3.0.1 : 59120053
Squeak 4.2 All-in-One : 3128033
Pharo Core 1.2 RC3 : 3828940
VA Smalltalk 7.5 : 19515614
Dolphin Professional 6.02 : 5097612
Amber 0.9.1 : 133367

Envois de messages par seconde

Envois de messages par seconde

Grosse surprise ici!  VisualSmalltalk domine!  Évidemment, VisualWorks suit de près tandis que Dolphin me déçoit encore!  J’ai toujours eu l’impression que Dolphin était fichtrement rapide mais ce n’était, hélas, qu’une impression!

Évidemment, la liste des versions de Smalltalk est loin d’être complète. J’essaierai, un  de ces jours, de refaire ce petit test (ou mieux, le Computer Language Benchmark) pour tous les environnements mentionnés ci-haut ainsi que les versions de Smalltalk suivantes:

Bref, toute cette histoire ne fait que commencer!  J’essaierai d’aboutir avec une version de tinyBenchmark pour toutes les versions de Smalltalk mentionnées dans cet article et qui roulent sur Windows… Éventuellement, je ferai la même chose pour le Shootout Benchmark…

À suivre!