cedardb与PostgreSQL语法兼容,但是直接运行结果是NULL,求解失败。将中间子查询的结果打印出来看出了原因。
同样的输入数据,输出的位掩码不同,比如初始化列和宫编码,数组中的元素值相同,顺序不同。
cedardb 输出
id board cols boxes
1 000000010400000000020000000000050407008000300001090000300400200050100000000806000 {12,64,32,18,1,14,137,272,129} {20,1,2,10,0,129,169,272,76}
PostgreSQL输出
1 | 000000010400000000020000000000050407008000300001090000300400200050100000000806000 | {12,18,129,137,272,32,14,1,64} | {10,0,1,129,272,76,20,169,2}
将相应的聚合函数 array_agg(m)改为明确的排序 array_agg(m ORDER BY c), 在cedardb 输出了与PostgreSQL相同的结果。
id board cols boxes
1 000000010400000000020000000000050407008000300001090000300400200050100000000806000 {12,18,129,137,272,32,14,1,64} {10,0,1,129,272,76,20,169,2}
再运行完整SQL,cedardb 求解出了示例数据的结果,时间约是PostgreSQL的十分之一。
PostgreSQL输出
id | puzzle | result
----+-----------+-----------
3 | 8????????+| 812753649+
| ??36?????+| 943682175+
| ?7??9?2??+| 675491283+
| ?5???7???+| 154237896+
| ????457??+| 369845721+
| ???1???3?+| 287169534+
| ??1????68+| 521974368+
| ??85???1?+| 438526917+
| ?9????4?? | 796318452
(1 row)
Time: 1211.606 ms (00:01.212)
cedardb 输出
id puzzle result
3 8????????
??36?????
?7??9?2??
?5???7???
????457??
???1???3?
??1????68
??85???1?
?9????4?? 812753649
943682175
675491283
154237896
369845721
287169534
521974368
438526917
796318452
2026-01-24 05:37:18.850220019 UTC INFO: [s] execution: (0.116115 min, 0.116115 max, 0.116115 median, 0.0% relMAD, 0.116115 avg, 0.000000 sdev, 4 scale, nan IPC, nan CPUs, nan GHz) compilation: (0.006032 min, 0.006032 max, 0.006032 median, 0.0% relMAD, 0.006032 avg, 0.000000 sdev)
但是如果是多个行,cedardb就报错了,看来是在生成执行计划阶段报错,原因还需要进一步研究。
2026-01-24 11:54:10.854135438 UTC FATAL: Assertion `(x != y) && (lca(x, y) == x)` failed. /cedardb/plan/algebra/operators/Operator.cpp:280: static cedar::algebra::Operator* cedar::algebra::Operator::LinkCutNode::findContainingChild(cedar::algebra::Operator*, cedar::algebra::Operator*)
CedarDB v2026-01-22 current-amd64
cedardb 0x31aff8b