Vous monitorez une instance MySQL, des comptes de dépenses, des accès à un serveur, etc ? Il existe des outils mathématiques pour vous faciliter la tâche et détecter les anomalies! Et ils sont expliqués dans l’article *Services Monitoring with Probabilistic Fault Detection*.

## Le monitoring et la détection probabiliste

19 mars 2017## Compiler magic

22 février 2017How do you efficiently divide by 19? All you need is some compiler magic! It’s all explained here!

## 1001001 SOS

10 février 2017I’ve been dealing a lot with *bit operations* lately. And doing lots of benchmarking, like here. As I was looking for a *bit count* method in Pharo (it used to be there but it no longer exists in Pharo 5.0), I got curious about the many different versions of bit counting algorithms I could find on the internet.

What’s so special about *bit operations* you ask? Not much. Except when you have to do it really fast on 64bit integers! Like in a chess program! Millions of times per position. So instead of copying the #bitCount method that was in Squeak, I decided I’d have a look at what is available on the net…

So I decided to share what I found. This could potentially be useful for people who have to deal with bit counting a lot. Especially if you deal with 14 bits or less!

Here’s a typical run of the different bit counting algorithms I have tested on Squeak 5.1 64bit.

Number of [myBitCount1 (128 bits)] per second: 0.061M Number of [myBitCount1 (14 bits)] per second: 1.417M Number of [myBitCount1 (16 bits)] per second: 1.271M Number of [myBitCount1 (30 bits)] per second: 0.698M Number of [myBitCount1 (32 bits)] per second: 0.651M Number of [myBitCount1 (60 bits)] per second: 0.362M Number of [myBitCount1 (64 bits)] per second: 0.131M Number of [myBitCount1 (8 bits)] per second: 2.255M Number of [myBitCount2 (128 bits)] per second: 0.286M Number of [myBitCount2 (14 bits)] per second: 3.623M Number of [myBitCount2 (16 bits)] per second: 3.630M Number of [myBitCount2 (30 bits)] per second: 2.320M Number of [myBitCount2 (32 bits)] per second: 2.336M Number of [myBitCount2 (60 bits)] per second: 1.415M Number of [myBitCount2 (64 bits)] per second: 1.208M Number of [myBitCount2 (8 bits)] per second: 4.950M Number of [myBitCount3 (128 bits)] per second: 0.498M Number of [myBitCount3 (14 bits)] per second: 4.556M Number of [myBitCount3 (16 bits)] per second: 4.673M Number of [myBitCount3 (30 bits)] per second: 3.401M Number of [myBitCount3 (32 bits)] per second: 3.401M Number of [myBitCount3 (60 bits)] per second: 2.130M Number of [myBitCount3 (64 bits)] per second: 1.674M Number of [myBitCount3 (8 bits)] per second: 4.938M Number of [myBitCount4 (128 bits)] per second: 0.041M Number of [myBitCount4 (14 bits)] per second: 5.333M Number of [myBitCount4 (16 bits)] per second: 4.819M Number of [myBitCount4 (30 bits)] per second: 2.841M Number of [myBitCount4 (32 bits)] per second: 2.674M Number of [myBitCount4 (60 bits)] per second: 1.499M Number of [myBitCount4 (64 bits)] per second: 0.270M Number of [myBitCount4 (8 bits)] per second: 7.435M Number of [myBitCount5 (128 bits)] per second: 0.377M Number of [myBitCount5 (14 bits)] per second: 3.937M Number of [myBitCount5 (16 bits)] per second: 3.035M Number of [myBitCount5 (30 bits)] per second: 2.137M Number of [myBitCount5 (32 bits)] per second: 2.035M Number of [myBitCount5 (60 bits)] per second: 1.386M Number of [myBitCount5 (64 bits)] per second: 1.188M Number of [myBitCount5 (8 bits)] per second: 4.167M Number of [myBitCount6 (128 bits)] per second: 0.381M Number of [myBitCount6 (14 bits)] per second: 5.195M Number of [myBitCount6 (16 bits)] per second: 3.552M Number of [myBitCount6 (30 bits)] per second: 2.488M Number of [myBitCount6 (32 bits)] per second: 2.364M Number of [myBitCount6 (60 bits)] per second: 1.555M Number of [myBitCount6 (64 bits)] per second: 1.284M Number of [myBitCount6 (8 bits)] per second: 5.571M Number of [myPopCount14bit (14 bits)] per second: 18.349M Number of [myPopCount14bit (8 bits)] per second: 18.519M Number of [myPopCount24bit (14 bits)] per second: 7.407M Number of [myPopCount24bit (16 bits)] per second: 7.463M Number of [myPopCount24bit (8 bits)] per second: 7.018M Number of [myPopCount32bit (14 bits)] per second: 4.963M Number of [myPopCount32bit (16 bits)] per second: 5.013M Number of [myPopCount32bit (30 bits)] per second: 4.608M Number of [myPopCount32bit (32 bits)] per second: 4.619M Number of [myPopCount32bit (8 bits)] per second: 4.608M Number of [myPopCount64a (14 bits)] per second: 2.778M Number of [myPopCount64a (16 bits)] per second: 2.793M Number of [myPopCount64a (30 bits)] per second: 2.751M Number of [myPopCount64a (32 bits)] per second: 2.703M Number of [myPopCount64a (60 bits)] per second: 2.809M Number of [myPopCount64a (64 bits)] per second: 1.385M Number of [myPopCount64a (8 bits)] per second: 2.755M Number of [myPopCount64b (14 bits)] per second: 3.063M Number of [myPopCount64b (16 bits)] per second: 3.096M Number of [myPopCount64b (30 bits)] per second: 3.106M Number of [myPopCount64b (32 bits)] per second: 3.053M Number of [myPopCount64b (60 bits)] per second: 3.008M Number of [myPopCount64b (64 bits)] per second: 1.444M Number of [myPopCount64b (8 bits)] per second: 3.091M Number of [myPopCount64c (14 bits)] per second: 1.625M Number of [myPopCount64c (16 bits)] per second: 1.600M Number of [myPopCount64c (30 bits)] per second: 1.542M Number of [myPopCount64c (32 bits)] per second: 1.529M Number of [myPopCount64c (60 bits)] per second: 1.566M Number of [myPopCount64c (64 bits)] per second: 1.082M Number of [myPopCount64c (8 bits)] per second: 3.945M

Now, since method *#myBitCount2* is similar to the *#bitCount* method in Squeak, that means there is still place for improvement as far as a faster #bitCount is needed. Now the question is : do we optimize it for the usual usage (SmallInteger), for 64bit integer or we use an algorithm that performs relatively well in most cases? Obviously, since I will always be working with 64bit positive integers, I have the luxury to pick a method that precisely works best in my specific case!

All test code I have used can be found here.

Note: Rush fans have probably noticed the reference in the title…

## Bits and Pieces

10 février 2017Often times, we take stuff for granted. But while preparing to embark on a crazy project (description in French here and Google translation in English here), I wanted to benchmark the *bit manipulation* operations in both Squeak and Pharo, for the 32bit and 64bit images (I am on Windows so the 64bit VM is not available for testing yet but it’ll come!). So essentially, it was just a test to compare the VM-Image-Environment combo!

To make a long story short, I was interested in testing the speed of 64bit operations on **positive integers** for my chess program. I quickly found some cases where LargePositiveInteger operations were more than 7-12 times slower than the SmallInteger equivalences and I became curious since it seemed like a lot. After more testing and discussions (both offline and online), someone suggested that some LargePositiveInteger operations could possibly be slow because they were not inlined in the JIT. It was then recommended that I override those methods in LargePositiveInteger (with primitives 34 to 37), thus shortcutting the default and slow methods in Integer (corresponding named primitives, *primDigitBitAnd*, *primDigitBitOr*, *primDigitBitXor*, *primDigitBitShiftMagnitude* in LargeIntegers module). I immediately got a 2-3x speedup for LargePositiveInteger but…

Things have obviously changed in the Squeak 64bit image since some original methods (in class Integer) like #bitAnd: and #bitOr: are way faster than the overrides (in class LargePositiveInteger )! Is it special code in the VM that checks for 32bit vs 64bit (more precisely, 30bit vs 60bit integers)? Is it in the LargeIntegers module?

Here are 2 typical runs for Squeak 5.1 32bit (by the way, Pharo 32bit image performs similarly) and Squeak 5.1 64bit images :

**Squeak 5.1 32bit**

Number of #allMask: per second: 7.637M Number of #anyMask: per second: 8.333M Number of #bitAnd: per second: 17.877M Number of #bitAnd2: per second: 42.105M Method #bitAnd2: seems to work properly! Overide of #bitAnd: in LargeInteger works! Number of #bitAt: per second: 12.075M Number of #bitAt:put: per second: 6.287M Number of #bitClear: per second: 6.737M Number of #bitInvert per second: 5.536M Number of #bitOr: per second: 15.764M Number of #bitOr2: per second: 34.409M Method #bitOr2: seems to work properly! Overide of #bitOr: in LargeInteger works! Method #bitShift2: (left & right shifts) seems to work properly! Overide of #bitShift: in LargeInteger works! Number of #bitXor: per second: 15.385M Number of #bitXor2: per second: 34.043M Method #bitXor2: seems to work properly! Overide of #bitXor: in LargeInteger works! Number of #highBit per second: 12.451M Number of #<< per second: 6.517M Number of #bitLeftShift2: per second: 8.399M Number of #lowBit per second: 10.702M Number of #noMask: per second: 7.064M Number of #>> per second: 7.323M Number of #bitRightShift2: per second: 29.358M

**Squeak 5.1 64bit**

Number of #allMask: per second: 36.782M Number of #anyMask: per second: 41.026M Number of #bitAnd: per second: 139.130M Number of #bitAnd2: per second: 57.143M Method #bitAnd2: seems to work properly! Overide of #bitAnd: in LargeInteger works! Number of #bitAt: per second: 23.358M Number of #bitAt:put: per second: 8.649M Number of #bitClear: per second: 38.554M Number of #bitInvert per second: 29.630M Number of #bitOr: per second: 139.130M Number of #bitOr2: per second: 58.182M Method #bitOr2: seems to work properly! Overide of #bitOr: in LargeInteger works! Method #bitShift2: (left & right shifts) seems to work properly! Overide of #bitShift: in LargeInteger works! Number of #bitXor: per second: 55.172M Number of #bitXor2: per second: 74.419M Method #bitXor2: seems to work properly! Overide of #bitXor: in LargeInteger works! Number of #highBit per second: 7.921M Number of #<< per second: 10.127M Number of #bitLeftShift2: per second: 12.800M Number of #lowBit per second: 6.823M Number of #noMask: per second: 39.024M Number of #>> per second: 23.188M Number of #bitRightShift2: per second: 56.140M

So now, I’m left with 2 questions :

- Why
**exactly**does the override work (in 32bit images)? - What changed so that things are different in Squeak 5.1 64bit image (overrides partially work)?

If you’re curious/interested, the code I have used to test is here.

Leave me a comment (or email) if you have an explanation!

To be continued…

## 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)

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 :

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.

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.

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).

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!

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

## Une grosse surprise

12 avril 2013Vous utilisez *AVG AntiVirus* et vous avez également installé *AVG Toolbar* dans votre fureteur préféré?

Sachez que le module *AVG Toolbar*, sans vous le dire, loggue une foule de renseignements sur les pages scannées et les connections effectuées à partir des pages web que vous consultez (principalement des publicités). Ces informations sont sauvegardées dans un fichier nommé *toolbar_log.txt* qu’on retrouve habituellement dans le répertoire :

*Documents and Settings\[NomDeLUsager]\Local Settings\Temp*

Le hic c’est que ce fichier ne fait que grossir sans arrêt! Quelle ne fut pas ma surprise de découvrir que celui-ci faisait 24 Gb sur ma machine!

Comment y remédier? Fermez votre fureteur, supprimez le fichier pis redémarrez votre ordi. Redémarrez votre fureteur puis fermez-le immédiatement. Retrouvez le fichier toolbar_log.txt et changez ses propriétés pour le mettre *read only.*

Tada! Fini les gigabytes de logs inutiles!