Here is the challenge: Database Programming Contest: Solve the 24-Point Card Game with One SQL Query, hosted by the database tooling platform NineData.
There is a table named cards. Its auto-incrementing numeric primary key is id, and it has 4 additional columns: c1, c2, c3, and c4. Each contains a random integer from 1 through 10. Contestants must use a single SQL statement to produce a formula that evaluates to 24, returning rows in the format shown on the right.
The result column contains the expression. Only 1 solution is required; if no solution exists, result should be NULL.
The rules of the 24-point game: only addition, subtraction, multiplication, and division are allowed—no factorials, exponentiation, or other operators. Each number must be used, and may be used only once. Parentheses may be used to change precedence.
The submission must be a single SQL statement. Built-in database functions are allowed, but stored procedures, user-defined functions, and code blocks are not.
Contestants can verify correctness against the demo database on NineData or against their own database. The judges’ evaluation server has 4 CPU cores and 32 GB of RAM.
Contestants must compete honestly and may not submit someone else’s code. If similar submissions are found, the organizers will recognize only the first one submitted.
Each contestant may submit at most 3 entries.
The submitted SQL must not exceed 10 KB.
The MySQL old hands at NineData gave their home team one hell of an edge in this contest. Here’s how.
Because that 10 KB limit is downright sneaky. The fastest solutions all use prime-number lookup tables, and concatenating the text for every solution takes roughly 10,018 characters. To squeeze that table under 10 KB, you need a few compression tricks.
MySQL ships with COMPRESS and UNCOMPRESS. Vanilla PostgreSQL does not; it needs the pgsql-gzip extension, which NineData’s contest platform does not provide.
Here is the PostgreSQL solution:
Create a Random Test Table#
CREATE SCHEMA poker24;
DROP TABLE IF EXISTS poker24.cards;
CREATE TABLE poker24.cards AS
SELECT i AS id,
ceil(random() * 10) AS c1,
ceil(random() * 10) AS c2,
ceil(random() * 10) AS c3,
ceil(random() * 10) AS c4
FROM generate_series(1, 1000000) i;
ALTER TABLE poker24.cards ADD PRIMARY KEY (id);Solution#
The basic idea is prime encoding: map every possible hand to a unique key, reducing the 24-point calculation to a fast lookup.
EXPLAIN ANALYZE
WITH a(i, result) AS (
SELECT (split_part(kv, ':', 1))::INTEGER AS i, split_part(kv, ':', 2) AS result
FROM regexp_split_to_table('152:((1+1)+1)*8,156:(6*2)*(1+1),204:(7+1)*(2+1),228:((1*1)+2)*8,276:(9-1)*(2+1),348:(10+2)*(1+1),140:(4*3)*(1+1),220:(5+1)*(3+1),260:((1+1)+6)*3,340:((1*1)+7)*3,380:(8*3)+(1-1),460:(9+3)*(1+1),580:(10-(1+1))*3,196:((1+1)+4)*4,308:((1*1)+5)*4,364:(6*4)+(1-1),476:(7-(1*1))*4,532:(8+4)*(1+1),644:(9-1)*(4-1),812:((1+1)*10)+4,484:(5*5)-(1*1),572:(5-(1*1))*6,748:(7+5)*(1+1),836:(5-(1+1))*8,676:(6+6)*(1+1),988:(8*6)/(1+1),1196:((1+1)*9)+6,1972:((1+1)*7)+10,1444:((1+1)*8)+8,126:(4*2)*(2+1),198:(2+2)*(5+1),234:(6+2)*(2+1),306:(2+2)*(7-1),342:((2-1)+2)*8,414:((2+1)+9)*2,522:(10-2)*(2+1),150:(3*2)*(3+1),210:((2+1)+3)*4,330:(5+3)*(2+1),390:((2-1)+3)*6,510:(7*3)+(2+1),570:(8*3)*(2-1),690:(9*3)-(2+1),870:(10-(2*1))*3,294:(4+4)*(2+1),462:((2-1)+5)*4,546:(6*4)*(2-1),714:(7-(2-1))*4,798:(4-(2-1))*8,966:(9-(2+1))*4,1218:((2*1)*10)+4,726:(5*5)-(2-1),858:(5-(2-1))*6,1122:(7+5)*(2*1),1254:(5-(2*1))*8,1518:((2+1)*5)+9,1914:(10*2)+(5-1),1014:((2+1)*6)+6,1326:(7-(2+1))*6,1482:(6-(2+1))*8,1794:((2*1)*9)+6,2262:((2+1)*10)-6,1734:((7*7)-1)/2,1938:(8*2)+(7+1),2346:(9*2)+(7-1),2958:((2*1)*7)+10,2166:((2*1)*8)+8,2622:(9*8)/(2+1),3306:((8-1)*2)+10,250:(3+3)*(3+1),350:((3+1)+4)*3,550:(5+3)*(3*1),650:((3-1)+6)*3,850:(7*3)+(3*1),950:((8+1)*3)-3,1150:(9-3)*(3+1),1450:(10-(3-1))*3,490:((3-1)+4)*4,770:(5*4)+(3+1),910:6/(1-(3/4)),1190:(7*4)-(3+1),1330:((3+1)*4)+8,1610:(9-(3*1))*4,2030:(10-4)*(3+1),1430:(6*3)+(5+1),1870:(7+5)*(3-1),2090:(5-(3-1))*8,2530:((3*1)*5)+9,3190:(10*3)-(5+1),1690:(6+6)*(3-1),2210:(7-(3*1))*6,2470:(8-(3+1))*6,2990:((3-1)*9)+6,3770:((3*1)*10)-6,2890:(7-3)*(7-1),3230:(7-(3+1))*8,3910:(9/3)*(7+1),4930:((3-1)*7)+10,3610:((3+1)*8)-8,4370:(9*8)/(3*1),5510:(8/3)*(10-1),5290:(9/3)*(9-1),6670:((10+1)*3)-9,8410:(10+10)+(3+1),686:((4+1)*4)+4,1078:(5*4)+(4*1),1274:((6+1)*4)-4,1666:(7*4)-(4*1),1862:((4*1)*4)+8,2254:(9-(4-1))*4,2842:(10-4)*(4*1),1694:(5*4)+(5-1),2002:6/((5/4)-1),2618:(7*4)-(5-1),2926:(8-4)*(5+1),3542:((4-1)*5)+9,4466:(10-4)*(5-1),2366:((4+1)*6)-6,3094:(7-(4-1))*6,3458:(6-(4-1))*8,4186:(9-(4+1))*6,5278:((4-1)*10)-6,4046:(7-4)*(7+1),4522:(7-(4*1))*8,5474:(7-4)*(9-1),5054:(8-(4+1))*8,6118:(9*8)/(4-1),9338:(10+9)+(4+1),11774:(10+10)+(4*1),2662:(5-(1/5))*5,3146:(6*5)-(5+1),5566:(9-5)*(5+1),7018:((10-5)*5)-1,3718:((5*1)*6)-6,4862:(6*5)-(7-1),5434:(8-(5-1))*6,6578:(9-(5*1))*6,8294:(10-6)*(5+1),7106:(7-(5-1))*8,8602:(9-5)*(7-1),10846:(7*5)-(10+1),7942:((5-1)*8)-8,9614:(9-(5+1))*8,12122:(10+8)+(5+1),11638:(9+9)+(5+1),14674:(10+9)+(5*1),18502:(10+10)+(5-1),4394:((6-1)*6)-6,6422:6/(1-(6/8)),7774:(9-(6-1))*6,9802:(10-6)*(6*1),10166:(9-6)*(7+1),12818:(10+7)+(6+1),9386:(8-(6-1))*8,11362:(9+8)+(6+1),14326:(10-(6+1))*8,13754:(9+9)+(6*1),17342:(10+9)+(6-1),13294:(9+7)+(7+1),16762:(10-7)*(7+1),12274:(8+8)+(7+1),14858:(9-(7-1))*8,18734:(10+8)+(7-1),17986:(9+9)+(7-1),22678:(10-7)*(9-1),13718:(8+8)+(8*1),16606:(9+8)+(8-1),20938:(10-(8-1))*8,135:(3*2)*(2+2),189:(4+2)*(2+2),297:((5*2)+2)*2,459:((7*2)-2)*2,513:(8-2)*(2+2),621:((9+2)*2)+2,783:(10*2)+(2+2),225:(3+3)*(2+2),315:((2+2)+4)*3,495:((5*2)-2)*3,585:((2/2)+3)*6,765:((2/2)+7)*3,855:(8*3)+(2-2),1035:(9-3)*(2+2),1305:((10+3)*2)-2,441:((4*2)-2)*4,693:(5*4)+(2+2),819:(6*4)+(2-2),1071:(7*4)-(2+2),1197:((2+2)*4)+8,1449:(9*2)+(4+2),1827:(10-4)*(2+2),1089:(5*5)-(2/2),1287:(5-(2/2))*6,1683:(7*2)+(5*2),1881:((8+5)*2)-2,2277:((5-2)+9)*2,2871:((5+2)*2)+10,1521:(6/2)*(6+2),1989:((7+2)*2)+6,2223:(8-(2+2))*6,2691:((6/2)+9)*2,3393:(10*2)+(6-2),2601:((7-2)+7)*2,2907:(7-(2+2))*8,4437:((10/2)+7)*2,3249:((2+2)*8)-8,3933:(9*2)+(8-2),4959:(10-2)+(8*2),6003:((9-2)*2)+10,7569:(10+10)+(2+2),375:((3+2)+3)*3,825:((5+2)*3)+3,975:((3-2)+3)*6,1275:((3-2)+7)*3,1425:(8*3)*(3-2),1725:((3+2)*3)+9,2175:(10*3)-(3*2),735:((3+2)*4)+4,1155:((3-2)+5)*4,1365:(6*4)*(3-2),1785:(7-(3-2))*4,1995:(4-(3-2))*8,2415:(9*4)/(3/2),3045:(10*3)-(4+2),1815:(5*5)-(3-2),2145:(5-(3-2))*6,2805:(7*3)+(5-2),3135:(5+3)+(8*2),3795:(9-5)*(3*2),4785:(5-3)*(10+2),2535:((3+2)*6)-6,3315:(7*3)+(6/2),3705:((8+2)*3)-6,4485:(9-(3+2))*6,5655:(10-6)*(3*2),4335:(7+3)+(7*2),4845:(8/3)*(7+2),5865:(9+7)*(3/2),7395:(7-3)+(10*2),5415:(8-(3+2))*8,6555:(9-(3*2))*8,8265:(10+8)+(3*2),7935:(9+9)+(3*2),10005:(10+9)+(3+2),12615:((10-3)*2)+10,1029:((4-2)+4)*4,1617:((5+2)*4)-4,1911:((4*2)-4)*6,2499:(7-4)*(4*2),2793:(8-4)*(4+2),3381:((9-2)*4)-4,4263:((4-2)*10)+4,2541:((5+5)*2)+4,3003:(6*5)-(4+2),3927:(7+5)*(4-2),4389:(5-(4-2))*8,5313:(9-5)*(4+2),6699:(10+4)+(5*2),3549:(6+6)*(4-2),4641:(7-4)*(6+2),5187:(8*6)/(4-2),6279:((4-2)*9)+6,7917:(10-6)*(4+2),6069:((7+7)*2)-4,6783:((7*2)-8)*4,8211:(9+7)+(4*2),10353:((4-2)*7)+10,7581:((4-2)*8)+8,9177:(9-(4+2))*8,11571:(10+8)+(4+2),11109:(9+9)+(4+2),14007:(10-4)+(9*2),17661:((4/10)+2)*10,6171:(5+5)+(7*2),6897:((5/5)+2)*8,8349:((5-2)*5)+9,10527:(5-(2/10))*5,5577:((5-2)*6)+6,7293:(7-(5-2))*6,8151:(6-(5-2))*8,9867:((5/2)*6)+9,12441:((5-2)*10)-6,9537:(7+7)+(5*2),10659:((5*2)-7)*8,12903:(7*5)-(9+2),16269:(10+7)+(5+2),11913:(8*5)-(8*2),14421:(9+8)+(5+2),18183:(10-(5+2))*8,22011:(9-5)+(10*2),27753:(10/5)*(10+2),6591:(6+6)+(6*2),8619:(7-(6/2))*6,9633:(8-(6-2))*6,11661:(9-6)*(6+2),14703:(10+6)+(6+2),12597:(7-(6-2))*8,15249:(9+7)+(6+2),19227:(10-7)*(6+2),14079:(8+8)+(6+2),17043:((6*2)-9)*8,21489:(10-8)*(6*2),20631:((9-6)+9)*2,26013:(9-6)*(10-2),32799:(10+10)+(6-2),16473:(8+7)+(7+2),25143:((10/7)+2)*7,18411:(8-(7-2))*8,22287:((9+7)*2)-8,34017:(10+9)+(7-2),42891:(10-7)*(10-2),20577:((8/2)*8)-8,24909:(9-(8-2))*8,31407:(10+8)+(8-2),30153:(9+9)+(8-2),38019:(10-(9-2))*8,47937:(10+10)+(8/2),58029:(10+9)+(10/2),625:((3*3)*3)-3,875:((3*3)-3)*4,1375:(5*3)+(3*3),1625:(6*3)+(3+3),2125:(7-3)*(3+3),2375:((3+3)-3)*8,2875:(9-(3/3))*3,3625:(10*3)-(3+3),1225:(4*3)+(4*3),1925:((3/3)+5)*4,2275:(6*4)+(3-3),2975:(7-(3/3))*4,3325:(8-4)*(3+3),4025:(9-(4-3))*3,3025:(5*5)-(3/3),3575:(6*5)-(3+3),4675:((5*3)-7)*3,6325:(9-5)*(3+3),7975:(10+5)+(3*3),4225:((6/3)+6)*3,5525:(7*3)+(6-3),6175:((3*3)-6)*8,7475:(9+6)+(3*3),9425:(10-6)*(3+3),7225:((3/7)+3)*7,8075:(8+7)+(3*3),9775:(9-3)*(7-3),9025:8/(3-(8/3)),10925:(9-(3+3))*8,13775:(10+8)+(3+3),13225:(9+9)+(3+3),16675:(10*3)-(9-3),1715:((4+3)*4)-4,2695:((4-3)+5)*4,3185:(6*4)*(4-3),4165:(7-(4-3))*4,4655:((4+3)-4)*8,5635:(9*4)-(4*3),7105:((10-3)*4)-4,4235:(5*5)-(4-3),5005:(5-(4-3))*6,6545:(7+5)+(4*3),7315:(8*4)-(5+3),8855:((5*3)-9)*4,11165:(10/5)*(4*3),5915:(6+6)+(4*3),8645:(8-6)*(4*3),10465:(9-(6-3))*4,13195:(10-4)+(6*3),10115:(7*4)-(7-3),11305:((7-3)*4)+8,13685:(9-7)*(4*3),17255:(10+7)+(4+3),15295:(9+8)+(4+3),19285:(10-(4+3))*8,18515:(9+9)*(4/3),29435:(10*3)-(10-4),7865:((5+5)*3)-6,10285:(7+5)*(5-3),11495:(8-5)*(5+3),13915:(9-(5/5))*3,9295:(6+6)*(5-3),12155:(7+5)*(6/3),13585:(8*6)/(5-3),16445:(9-6)*(5+3),20735:(10+6)+(5+3),17765:(8-5)+(7*3),21505:(9+7)+(5+3),27115:(10-7)*(5+3),19855:(8+8)+(5+3),24035:(9*3)-(8-5),29095:((5/3)*9)+9,36685:(10/5)*(9+3),46255:(10-(10/5))*3,10985:((6-3)*6)+6,14365:(7-(6-3))*6,16055:((6+3)-6)*8,19435:(9+6)+(6+3),24505:((6-3)*10)-6,18785:((7-6)+7)*3,20995:(8+7)+(6+3),25415:(9-6)+(7*3),32045:((6/3)*7)+10,23465:((6/3)*8)+8,28405:(9*8)/(6-3),35815:(10-(8-6))*3,34385:(9*3)-(9-6),43355:(10-6)*(9-3),54665:(3-(6/10))*10,24565:(7+7)+(7+3),27455:((7+3)-7)*8,33235:(9-(7/7))*3,41905:(10-7)+(7*3),30685:((7-3)*8)-8,37145:(9-(8-7))*3,44965:(9-7)*(9+3),56695:(9*3)-(10-7),71485:(10+10)+(7-3),34295:((8+3)-8)*8,41515:(9-8)*(8*3),52345:((10*8)-8)/3,50255:(9-9)+(8*3),63365:(10+9)+(8-3),79895:(10-10)+(8*3),60835:(9+9)+(9-3),76705:((9+9)-10)*3,96715:(9-(10/10))*3,2401:(4*4)+(4+4),3773:((4/4)+5)*4,4459:((4+4)-4)*6,5831:(7-4)*(4+4),6517:(8*4)-(4+4),7889:((9-4)*4)+4,9947:(10*4)-(4*4),5929:(5*5)-(4/4),7007:(5-(4/4))*6,9163:(7-(5-4))*4,10241:(8-5)*(4+4),15631:((10-5)*4)+4,12103:(8+4)*(6-4),14651:(9-6)*(4+4),18473:(10+6)+(4+4),14161:(4-(4/7))*7,15827:(7*4)-(8-4),19159:(9+7)+(4+4),24157:(10-7)*(4+4),17689:(8+8)+(4+4),21413:(9*4)-(8+4),26999:(10-4)*(8-4),41209:((10*10)-4)/4,9317:(5*5)-(5-4),11011:((5+4)-5)*6,14399:(7-(5/5))*4,16093:(4-(5/5))*8,19481:(9-5)+(5*4),24563:(10+5)+(5+4),13013:(6-5)*(6*4),17017:(7+5)*(6-4),19019:((5+4)-6)*8,23023:(9+6)+(5+4),29029:(10-6)+(5*4),22253:(7*5)-(7+4),24871:(8+7)+(5+4),30107:((7-4)*5)+9,37961:((7-5)*10)+4,27797:(5-(8/4))*8,33649:(9-(8-5))*4,42427:(10/5)*(8+4),40733:((9/9)+5)*4,51359:(9-5)*(10-4),64757:((10/5)*10)+4,15379:((6+4)-6)*6,20111:(7-6)*(6*4),22477:(8+6)+(6+4),27209:((6-4)*9)+6,34307:(10+6)*(6/4),26299:(7+7)+(6+4),29393:((6+4)-7)*8,35581:(9+7)*(6/4),44863:((6-4)*7)+10,32851:((6-4)*8)+8,39767:(9-8)*(6*4),50141:((8-6)*10)+4,48139:(9-9)+(6*4),60697:(10-9)*(6*4),76531:(10-10)+(6*4),34391:(7-(7/7))*4,38437:((7+7)-8)*4,42959:((7+4)-8)*8,52003:(9*8)/(7-4),65569:((7/4)*8)+10,62951:(7-(9/9))*4,79373:(10*4)-(9+7),100079:(7-(10/10))*4,48013:((8-4)*8)-8,58121:((8+4)-9)*8,73283:(10-8)*(8+4),70357:(4-(9/9))*8,88711:((9+4)-10)*8,111853:(10+10)+(8-4),107387:(10+9)+(9-4),14641:(5*5)-(5/5),17303:(5*5)-(6-5),30613:(9+5)+(5+5),20449:((5+5)-6)*6,26741:(5*5)-(7-6),29887:(8+6)+(5+5),34969:(7+7)+(5+5),39083:((5+5)-7)*8,59653:(10/5)*(7+5),43681:(5*5)-(8/8),52877:(5*5)-(9-8),66671:(10+5)*(8/5),64009:(5*5)-(9/9),80707:(5*5)-(10-9),101761:(5*5)-(10/10),24167:(5-(6/6))*6,31603:(7+6)+(6+5),35321:((8-5)*6)+6,42757:(9*6)-(6*5),53911:((10-5)*6)-6,41327:(5-(7/7))*6,46189:(8-6)*(7+5),55913:((7-5)*9)+6,51623:((6+5)-8)*8,62491:((8+5)-9)*6,78793:(6*5)/(10/8),75647:((9-6)*5)+9,95381:((9+5)-10)*6,120263:(10+10)*(6/5),73117:(9-7)*(7+5),92191:((7-5)*7)+10,67507:((7-5)*8)+8,81719:((7+5)-9)*8,103037:(10-8)*(7+5),124729:((10-7)*5)+9,157267:((7/5)*10)+10,75449:(8*5)-(8+8),91333:(9*8)/(8-5),115159:((8+5)-10)*8,212773:(10+10)+(9-5),28561:(6+6)+(6+6),41743:(8-6)*(6+6),50531:(6*6)/(9/6),63713:(10*6)-(6*6),66079:(9-7)*(6+6),83317:((10-7)*6)+6,61009:(8*6)/(8-6),73853:((6+6)-9)*8,93119:(10-8)*(6+6),112723:((9-6)*10)-6,108953:((7+7)-10)*6,96577:(8*6)/(9-7),121771:((7+6)-10)*8,116909:(7*6)-(9+9),185861:((10-7)*10)-6,89167:((8-6)*8)+8,107939:(9*8)-(8*6),136097:(8*6)/(10-8),130663:(9+9)*(8/6),164749:((10-8)*9)+6,199433:((9/6)*10)+9,317057:(10+10)+(10-6),192763:((9-7)*7)+10,141151:((9-7)*8)+8,177973:(10*8)-(8*7),215441:(9*8)/(10-7),271643:((10-8)*7)+10,198911:((10-8)*8)+8', ',') AS kv
)
SELECT c.id, c1, c2, c3, c4, result
FROM poker24.cards c LEFT JOIN a a ON a.i =
( CASE c1 WHEN 1 THEN 2 WHEN 2 THEN 3 WHEN 3 THEN 5 WHEN 4 THEN 7 WHEN 5 THEN 11 WHEN 6 THEN 13 WHEN 7 THEN 17 WHEN 8 THEN 19 WHEN 9 THEN 23 WHEN 10 THEN 29 END
* CASE c2 WHEN 1 THEN 2 WHEN 2 THEN 3 WHEN 3 THEN 5 WHEN 4 THEN 7 WHEN 5 THEN 11 WHEN 6 THEN 13 WHEN 7 THEN 17 WHEN 8 THEN 19 WHEN 9 THEN 23 WHEN 10 THEN 29 END
* CASE c3 WHEN 1 THEN 2 WHEN 2 THEN 3 WHEN 3 THEN 5 WHEN 4 THEN 7 WHEN 5 THEN 11 WHEN 6 THEN 13 WHEN 7 THEN 17 WHEN 8 THEN 19 WHEN 9 THEN 23 WHEN 10 THEN 29 END
* CASE c4 WHEN 1 THEN 2 WHEN 2 THEN 3 WHEN 3 THEN 5 WHEN 4 THEN 7 WHEN 5 THEN 11 WHEN 6 THEN 13 WHEN 7 THEN 17 WHEN 8 THEN 19 WHEN 9 THEN 23 WHEN 10 THEN 29 END);The query text here is over 10,000 characters—10,896, to be exact. There are several ways to trim it: turn that enormous CASE into an inline function, then replace the decimal primary-key literals with hexadecimal ones, and the query would fit under 10 KB.
But the rules forbid user-defined functions and stored procedures, so we need another route. The real problem is how to compress that giant string in the middle.
Compression#
Again, the query text is over 10,000 characters—10,896, to be exact. We therefore need extra compression support to meet the contest limit. Pigsty ships with the pgsql-gzip extension:
CREATE EXTENSION IF NOT EXISTS gzip;Compressing the result table above cuts it from 10,018 characters to 7,796, bringing the total query length to 8,796—comfortably within the limit.
WITH a(i, result) AS (SELECT (split_part(kv, ':', 1))::INTEGER AS i, split_part(kv, ':', 2) AS result
FROM regexp_split_to_table(encode(gunzip('\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escape'), ',') AS kv)
SELECT c.id, c1, c2, c3, c4, result FROM poker24.cards c LEFT JOIN a a ON a.i =
(CASE c1 WHEN 1 THEN 2 WHEN 2 THEN 3 WHEN 3 THEN 5 WHEN 4 THEN 7 WHEN 5 THEN 11 WHEN 6 THEN 13 WHEN 7 THEN 17 WHEN 8 THEN 19 WHEN 9 THEN 23 WHEN 10 THEN 29 END
*CASE c2 WHEN 1 THEN 2 WHEN 2 THEN 3 WHEN 3 THEN 5 WHEN 4 THEN 7 WHEN 5 THEN 11 WHEN 6 THEN 13 WHEN 7 THEN 17 WHEN 8 THEN 19 WHEN 9 THEN 23 WHEN 10 THEN 29 END
*CASE c3 WHEN 1 THEN 2 WHEN 2 THEN 3 WHEN 3 THEN 5 WHEN 4 THEN 7 WHEN 5 THEN 11 WHEN 6 THEN 13 WHEN 7 THEN 17 WHEN 8 THEN 19 WHEN 9 THEN 23 WHEN 10 THEN 29 END
*CASE c4 WHEN 1 THEN 2 WHEN 2 THEN 3 WHEN 3 THEN 5 WHEN 4 THEN 7 WHEN 5 THEN 11 WHEN 6 THEN 13 WHEN 7 THEN 17 WHEN 8 THEN 19 WHEN 9 THEN 23 WHEN 10 THEN 29 END);Results#
On my local M1 MacBook Pro, the single-core execution time is about 0.58 seconds, slightly faster than the winning entry’s 0.67 seconds.
Of course, NineData’s PostgreSQL instance does not have the gzip extension, so I did not submit this result on their 4-core, 32 GB platform.
Merge Right Join (cost=118104.17..768224.17 rows=5000000 width=68) (actual time=457.485..555.265 rows=1000000 loops=1)
Merge Cond: (((split_part(kv.kv, ':'::text, 1))::integer) = ((((CASE c.c1 WHEN '1'::double precision THEN 2 WHEN '2'::double precision THEN 3 WHEN '3'::double precision THEN 5 WHEN '4'::double precision THEN 7 WHEN '5'::double precision THEN 11 WHEN '6'::double precision THEN 13 WHEN '7'::double precision THEN 17 WHEN '8'::double precision THEN 19 WHEN '9'::double precision THEN 23 WHEN '10'::double precision THEN 29 ELSE NULL::integer END * CASE c.c2 WHEN '1'::double precision THEN 2 WHEN '2'::double precision THEN 3 WHEN '3'::double precision THEN 5 WHEN '4'::double precision THEN 7 WHEN '5'::double precision THEN 11 WHEN '6'::double precision THEN 13 WHEN '7'::double precision THEN 17 WHEN '8'::double precision THEN 19 WHEN '9'::double precision THEN 23 WHEN '10'::double precision THEN 29 ELSE NULL::integer END) * CASE c.c3 WHEN '1'::double precision THEN 2 WHEN '2'::double precision THEN 3 WHEN '3'::double precision THEN 5 WHEN '4'::double precision THEN 7 WHEN '5'::double precision THEN 11 WHEN '6'::double precision THEN 13 WHEN '7'::double precision THEN 17 WHEN '8'::double precision THEN 19 WHEN '9'::double precision THEN 23 WHEN '10'::double precision THEN 29 ELSE NULL::integer END) * CASE c.c4 WHEN '1'::double precision THEN 2 WHEN '2'::double precision THEN 3 WHEN '3'::double precision THEN 5 WHEN '4'::double precision THEN 7 WHEN '5'::double precision THEN 11 WHEN '6'::double precision THEN 13 WHEN '7'::double precision THEN 17 WHEN '8'::double precision THEN 19 WHEN '9'::double precision THEN 23 WHEN '10'::double precision THEN 29 ELSE NULL::integer END)))
-> Sort (cost=62.33..64.83 rows=1000 width=64) (actual time=0.851..0.872 rows=566 loops=1)
Sort Key: ((split_part(kv.kv, ':'::text, 1))::integer)
Sort Method: quicksort Memory: 59kB
-> Function Scan on regexp_split_to_table kv (cost=0.00..12.50 rows=1000 width=64) (actual time=0.491..0.654 rows=566 loops=1)
-> Sort (cost=118041.84..120541.84 rows=1000000 width=36) (actual time=456.629..494.693 rows=1000000 loops=1)
Sort Key: ((((CASE c.c1 WHEN '1'::double precision THEN 2 WHEN '2'::double precision THEN 3 WHEN '3'::double precision THEN 5 WHEN '4'::double precision THEN 7 WHEN '5'::double precision THEN 11 WHEN '6'::double precision THEN 13 WHEN '7'::double precision THEN 17 WHEN '8'::double precision THEN 19 WHEN '9'::double precision THEN 23 WHEN '10'::double precision THEN 29 ELSE NULL::integer END * CASE c.c2 WHEN '1'::double precision THEN 2 WHEN '2'::double precision THEN 3 WHEN '3'::double precision THEN 5 WHEN '4'::double precision THEN 7 WHEN '5'::double precision THEN 11 WHEN '6'::double precision THEN 13 WHEN '7'::double precision THEN 17 WHEN '8'::double precision THEN 19 WHEN '9'::double precision THEN 23 WHEN '10'::double precision THEN 29 ELSE NULL::integer END) * CASE c.c3 WHEN '1'::double precision THEN 2 WHEN '2'::double precision THEN 3 WHEN '3'::double precision THEN 5 WHEN '4'::double precision THEN 7 WHEN '5'::double precision THEN 11 WHEN '6'::double precision THEN 13 WHEN '7'::double precision THEN 17 WHEN '8'::double precision THEN 19 WHEN '9'::double precision THEN 23 WHEN '10'::double precision THEN 29 ELSE NULL::integer END) * CASE c.c4 WHEN '1'::double precision THEN 2 WHEN '2'::double precision THEN 3 WHEN '3'::double precision THEN 5 WHEN '4'::double precision THEN 7 WHEN '5'::double precision THEN 11 WHEN '6'::double precision THEN 13 WHEN '7'::double precision THEN 17 WHEN '8'::double precision THEN 19 WHEN '9'::double precision THEN 23 WHEN '10'::double precision THEN 29 ELSE NULL::integer END))
Sort Method: external sort Disk: 56760kB
-> Seq Scan on cards c (cost=0.00..18384.00 rows=1000000 width=36) (actual time=0.028..213.760 rows=1000000 loops=1)
Planning Time: 0.363 ms
Execution Time: 581.782 msAnd that is how to solve the 24-point card game in PostgreSQL with a single SQL statement.
Parallelism might shave off even more time. PostgreSQL also offers another approach that other databases cannot match: package the lookup into an extension and expose it directly to SQL as a C routine. That would optimize this computation about as far as it can go. But honestly, we couldn’t be bothered.
