FAIRYFAR-INTERNAL wiki:Public-Project:调研
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2026-05-05T17:19:46+0800
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2023-06-17T21:25:19+0800
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wiki:Public-Project:调研:CRC32函数性能测试
http://200yi.com/ff_internal/wiki.php?id=wiki:Public-Project:%E8%B0%83%E7%A0%94:CRC32%E5%87%BD%E6%95%B0%E6%80%A7%E8%83%BD%E6%B5%8B%E8%AF%95&rev=1687008319&do=diff
测试条件：单线程，1亿次计算（分1000组，每组100000次），每条数据宽64Byte。
单位：s
Round 1 Round 2 Round 3 AVG. --------------- ----------- ----------- ----------- -------- CRC32 13.551
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2023-06-17T21:25:19+0800
Anonymous (anonymous@undisclosed.example.com)
wiki:Public-Project:调研:TPC-H Q07 Or执行计划优化
http://200yi.com/ff_internal/wiki.php?id=wiki:Public-Project:%E8%B0%83%E7%A0%94:TPC-H%20Q07%20Or%E6%89%A7%E8%A1%8C%E8%AE%A1%E5%88%92%E4%BC%98%E5%8C%96&rev=1687008319&do=diff
一、布尔运算推演
已知，
A∩(B∪C) = (A∩C)∪(A∪C)
A∪(B∩C) = (A∪C)∩(A∪C)
A∩A = A
(A∩B)∩C = A∩B∩C = A∩C∩B
那么，
(A∩B)∪(C∩D) = ((A∩B)∪C) ∩ ((A∩B)∪D)
= ((A∪C)∩(B∪C)) ∩ ((A∪D)∩(B∪D))
= (A∪C) ∩ (B∪C) ∩ (A∪D) ∩ (B∪D)
=> ((A∩B)∪(C∩D)) ∩ (A∪C) ∩ (B∪D) = (A∪C) ∩ (B∪C) ∩ (A∪D) ∩ (B∪D) ∩ (A∪C) ∩ (B∪D)
=> ((A∩B)∪(C∩D)) ∩ (A∪C) ∩ (B∪D) = (A∪C) ∩ (B∪C) ∩ (A∪D) ∩ (B∪D)
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