\u5927\u6570\u636e\u91cf\u7684\u95ee\u9898\u662f\u5f88\u591a\u9762\u8bd5\u7b14\u8bd5\u4e2d\u7ecf\u5e38\u51fa\u73b0\u7684\u95ee\u9898\uff0c\u6bd4\u5982baidu google \u817e\u8baf\u8fd9\u6837\u7684\u4e00\u4e9b\u6d89\u53ca\u5230\u6d77\u91cf\u6570\u636e\u7684\u516c\u53f8\u7ecf\u5e38\u4f1a\u95ee\u5230\u3002<\/p>\n
\u4e0b\u9762\u7684\u65b9\u6cd5\u662f\u6211\u5bf9\u6d77\u91cf\u6570\u636e\u7684\u5904\u7406\u65b9\u6cd5\u8fdb\u884c\u4e86\u4e00\u4e2a\u4e00\u822c\u6027\u7684\u603b\u7ed3\uff0c\u5f53\u7136\u8fd9\u4e9b\u65b9\u6cd5\u53ef\u80fd\u5e76\u4e0d\u80fd\u5b8c\u5168\u8986\u76d6\u6240\u6709\u7684\u95ee\u9898\uff0c\u4f46\u662f\u8fd9\u6837\u7684\u4e00\u4e9b\u65b9\u6cd5\u4e5f\u57fa\u672c\u53ef\u4ee5\u5904\u7406\u7edd\u5927\u591a\u6570\u9047\u5230\u7684\u95ee\u9898\u3002\u4e0b\u9762\u7684\u4e00\u4e9b\u95ee\u9898\u57fa\u672c\u76f4\u63a5\u6765\u6e90\u4e8e\u516c\u53f8\u7684\u9762\u8bd5\u7b14\u8bd5\u9898\u76ee\uff0c\u65b9\u6cd5\u4e0d\u4e00\u5b9a\u6700\u4f18\uff0c\u5982\u679c\u4f60\u6709\u66f4\u597d\u7684\u5904\u7406\u65b9\u6cd5\uff0c\u6b22\u8fce\u4e0e\u6211\u8ba8\u8bba\u3002<\/p>\n
1.Bloom filter<\/p>\n
\u9002\u7528\u8303\u56f4\uff1a\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u6570\u636e\u5b57\u5178\uff0c\u8fdb\u884c\u6570\u636e\u7684\u5224\u91cd\uff0c\u6216\u8005\u96c6\u5408\u6c42\u4ea4\u96c6<\/p>\n
\u57fa\u672c\u539f\u7406\u53ca\u8981\u70b9\uff1a
\u5bf9\u4e8e\u539f\u7406\u6765\u8bf4\u5f88\u7b80\u5355\uff0c\u4f4d\u6570\u7ec4+k\u4e2a\u72ec\u7acbhash\u51fd\u6570\u3002\u5c06hash\u51fd\u6570\u5bf9\u5e94\u7684\u503c\u7684\u4f4d\u6570\u7ec4\u7f6e1\uff0c\u67e5\u627e\u65f6\u5982\u679c\u53d1\u73b0\u6240\u6709hash\u51fd\u6570\u5bf9\u5e94\u4f4d\u90fd\u662f1\u8bf4\u660e\u5b58\u5728\uff0c\u5f88\u660e\u663e\u8fd9\u4e2a\u8fc7\u7a0b\u5e76\u4e0d\u4fdd\u8bc1\u67e5\u627e\u7684\u7ed3\u679c\u662f100%\u6b63\u786e\u7684\u3002\u540c\u65f6\u4e5f\u4e0d\u652f\u6301\u5220\u9664\u4e00\u4e2a\u5df2\u7ecf\u63d2\u5165\u7684\u5173\u952e\u5b57\uff0c\u56e0\u4e3a\u8be5\u5173\u952e\u5b57\u5bf9\u5e94\u7684\u4f4d\u4f1a\u7275\u52a8\u5230\u5176\u4ed6\u7684\u5173\u952e\u5b57\u3002\u6240\u4ee5\u4e00\u4e2a\u7b80\u5355\u7684\u6539\u8fdb\u5c31\u662f counting Bloom filter\uff0c\u7528\u4e00\u4e2acounter\u6570\u7ec4\u4ee3\u66ff\u4f4d\u6570\u7ec4\uff0c\u5c31\u53ef\u4ee5\u652f\u6301\u5220\u9664\u4e86\u3002<\/p>\n
\u8fd8\u6709\u4e00\u4e2a\u6bd4\u8f83\u91cd\u8981\u7684\u95ee\u9898\uff0c\u5982\u4f55\u6839\u636e\u8f93\u5165\u5143\u7d20\u4e2a\u6570n\uff0c\u786e\u5b9a\u4f4d\u6570\u7ec4m\u7684\u5927\u5c0f\u53cahash\u51fd\u6570\u4e2a\u6570\u3002\u5f53hash\u51fd\u6570\u4e2a\u6570k=(ln2)*(m\/n)\u65f6\u9519\u8bef\u7387\u6700\u5c0f\u3002\u5728\u9519\u8bef\u7387\u4e0d\u5927\u4e8eE\u7684\u60c5\u51b5\u4e0b\uff0cm \u81f3\u5c11\u8981\u7b49\u4e8en*lg(1\/E)\u624d\u80fd\u8868\u793a\u4efb\u610fn\u4e2a\u5143\u7d20\u7684\u96c6\u5408\u3002\u4f46m\u8fd8\u5e94\u8be5\u66f4\u5927\u4e9b\uff0c\u56e0\u4e3a\u8fd8\u8981\u4fdd\u8bc1bit\u6570\u7ec4\u91cc\u81f3\u5c11\u4e00\u534a\u4e3a0\uff0c\u5219m\u5e94\u8be5>=nlg(1 \/E)*lge \u5927\u6982\u5c31\u662fnlg(1\/E)1.44\u500d(lg\u8868\u793a\u4ee52\u4e3a\u5e95\u7684\u5bf9\u6570)\u3002<\/p>\n
\u4e3e\u4e2a\u4f8b\u5b50\u6211\u4eec\u5047\u8bbe\u9519\u8bef\u7387\u4e3a0.01\uff0c\u5219\u6b64\u65f6m\u5e94\u5927\u6982 \u662fn\u768413\u500d\u3002\u8fd9\u6837k\u5927\u6982\u662f8\u4e2a\u3002<\/p>\n
\u6ce8\u610f\u8fd9\u91ccm\u4e0en\u7684\u5355\u4f4d\u4e0d\u540c\uff0cm\u662fbit\u4e3a\u5355\u4f4d\uff0c\u800cn\u5219\u662f\u4ee5\u5143\u7d20\u4e2a\u6570\u4e3a\u5355\u4f4d(\u51c6\u786e\u7684\u8bf4\u662f\u4e0d\u540c\u5143\u7d20\u7684\u4e2a\u6570)\u3002\u901a\u5e38\u5355\u4e2a\u5143\u7d20\u7684\u957f\u5ea6\u90fd\u662f\u6709\u5f88\u591abit\u7684\u3002\u6240\u4ee5\u4f7f\u7528bloom filter\u5185\u5b58\u4e0a\u901a\u5e38\u90fd\u662f\u8282\u7701\u7684\u3002<\/p>\n
\u6269\u5c55\uff1a
Bloom filter\u5c06\u96c6\u5408\u4e2d\u7684\u5143\u7d20\u6620\u5c04\u5230\u4f4d\u6570\u7ec4\u4e2d\uff0c\u7528k\uff08k\u4e3a\u54c8\u5e0c\u51fd\u6570\u4e2a\u6570\uff09\u4e2a\u6620\u5c04\u4f4d\u662f\u5426\u51681\u8868\u793a\u5143\u7d20\u5728\u4e0d\u5728\u8fd9\u4e2a\u96c6\u5408\u4e2d\u3002Counting bloom filter\uff08CBF\uff09\u5c06\u4f4d\u6570\u7ec4\u4e2d\u7684\u6bcf\u4e00\u4f4d\u6269\u5c55\u4e3a\u4e00\u4e2acounter\uff0c\u4ece\u800c\u652f\u6301\u4e86\u5143\u7d20\u7684\u5220\u9664\u64cd\u4f5c\u3002Spectral Bloom Filter\uff08SBF\uff09\u5c06\u5176\u4e0e\u96c6\u5408\u5143\u7d20\u7684\u51fa\u73b0\u6b21\u6570\u5173\u8054\u3002SBF\u91c7\u7528counter\u4e2d\u7684\u6700\u5c0f\u503c\u6765\u8fd1\u4f3c\u8868\u793a\u5143\u7d20\u7684\u51fa\u73b0\u9891\u7387\u3002<\/p>\n
\u95ee\u9898\u5b9e\u4f8b\uff1a\u7ed9\u4f60 A,B\u4e24\u4e2a\u6587\u4ef6\uff0c\u5404\u5b58\u653e50\u4ebf\u6761URL\uff0c\u6bcf\u6761URL\u5360\u752864\u5b57\u8282\uff0c\u5185\u5b58\u9650\u5236\u662f4G\uff0c\u8ba9\u4f60\u627e\u51faA,B\u6587\u4ef6\u5171\u540c\u7684URL\u3002\u5982\u679c\u662f\u4e09\u4e2a\u4e43\u81f3n\u4e2a\u6587\u4ef6\u5462\uff1f<\/p>\n
\u6839\u636e\u8fd9\u4e2a\u95ee\u9898\u6211\u4eec\u6765\u8ba1\u7b97\u4e0b\u5185\u5b58\u7684\u5360\u7528\uff0c4G=2^32\u5927\u6982\u662f40\u4ebf*8\u5927\u6982\u662f340\u4ebf\uff0cn=50\u4ebf\uff0c\u5982\u679c\u6309\u51fa\u9519\u73870.01\u7b97\u9700\u8981\u7684\u5927\u6982\u662f650\u4ebf\u4e2abit\u3002\u73b0\u5728\u53ef\u7528\u7684\u662f340\u4ebf\uff0c\u76f8\u5dee\u5e76\u4e0d\u591a\uff0c\u8fd9\u6837\u53ef\u80fd\u4f1a\u4f7f\u51fa\u9519\u7387\u4e0a\u5347\u4e9b\u3002\u53e6\u5916\u5982\u679c\u8fd9\u4e9burlip\u662f\u4e00\u4e00\u5bf9\u5e94\u7684\uff0c\u5c31\u53ef\u4ee5\u8f6c\u6362\u6210ip\uff0c\u5219\u5927\u5927\u7b80\u5355\u4e86\u3002<\/p>\n
2.Hashing<\/p>\n
\u9002\u7528\u8303\u56f4\uff1a\u5feb\u901f\u67e5\u627e\uff0c\u5220\u9664\u7684\u57fa\u672c\u6570\u636e\u7ed3\u6784\uff0c\u901a\u5e38\u9700\u8981\u603b\u6570\u636e\u91cf\u53ef\u4ee5\u653e\u5165\u5185\u5b58<\/p>\n
\u57fa\u672c\u539f\u7406\u53ca\u8981\u70b9\uff1a
hash\u51fd\u6570\u9009 \u62e9\uff0c\u9488\u5bf9\u5b57\u7b26\u4e32\uff0c\u6574\u6570\uff0c\u6392\u5217\uff0c\u5177\u4f53\u76f8\u5e94\u7684hash\u65b9\u6cd5\u3002
\u78b0\u649e\u5904\u7406\uff0c\u4e00\u79cd\u662fopen hashing\uff0c\u4e5f\u79f0\u4e3a\u62c9\u94fe\u6cd5\uff1b\u53e6\u4e00\u79cd\u5c31\u662fclosed hashing\uff0c\u4e5f\u79f0\u5f00\u5730\u5740\u6cd5\uff0copened addressing\u3002<\/p>\n
\u6269\u5c55\uff1a
d-left hashing\u4e2d\u7684d\u662f\u591a\u4e2a\u7684\u610f\u601d\uff0c\u6211\u4eec\u5148\u7b80\u5316\u8fd9\u4e2a\u95ee\u9898\uff0c\u770b\u4e00\u770b2-left hashing\u30022-left hashing\u6307\u7684\u662f\u5c06\u4e00\u4e2a\u54c8\u5e0c\u8868\u5206\u6210\u957f\u5ea6\u76f8\u7b49\u7684\u4e24\u534a\uff0c\u5206\u522b\u53eb\u505aT1\u548cT2\uff0c\u7ed9T1\u548cT2\u5206\u522b\u914d\u5907\u4e00\u4e2a\u54c8\u5e0c\u51fd\u6570\uff0ch1\u548ch2\u3002\u5728\u5b58\u50a8\u4e00\u4e2a\u65b0\u7684key\u65f6\uff0c\u540c\u65f6\u7528\u4e24\u4e2a\u54c8\u5e0c\u51fd\u6570\u8fdb\u884c\u8ba1\u7b97\uff0c\u5f97\u51fa\u4e24\u4e2a\u5730\u5740h1[key]\u548ch2[key]\u3002\u8fd9\u65f6\u9700\u8981\u68c0\u67e5T1\u4e2d\u7684h1[key]\u4f4d\u7f6e\u548cT2\u4e2d\u7684h2[key]\u4f4d\u7f6e\uff0c\u54ea\u4e00\u4e2a\u4f4d\u7f6e\u5df2\u7ecf\u5b58\u50a8\u7684\uff08\u6709\u78b0\u649e\u7684\uff09key\u6bd4\u8f83\u591a\uff0c\u7136\u540e\u5c06\u65b0key\u5b58\u50a8\u5728\u8d1f\u8f7d\u5c11\u7684\u4f4d\u7f6e\u3002\u5982\u679c\u4e24\u8fb9\u4e00\u6837\u591a\uff0c\u6bd4\u5982\u4e24\u4e2a\u4f4d\u7f6e\u90fd\u4e3a\u7a7a\u6216\u8005\u90fd\u5b58\u50a8\u4e86\u4e00\u4e2akey\uff0c\u5c31\u628a\u65b0key \u5b58\u50a8\u5728\u5de6\u8fb9\u7684T1\u5b50\u8868\u4e2d\uff0c2-left\u4e5f\u7531\u6b64\u800c\u6765\u3002\u5728\u67e5\u627e\u4e00\u4e2akey\u65f6\uff0c\u5fc5\u987b\u8fdb\u884c\u4e24\u6b21hash\uff0c\u540c\u65f6\u67e5\u627e\u4e24\u4e2a\u4f4d\u7f6e\u3002<\/p>\n
\u95ee\u9898\u5b9e\u4f8b\uff1a
1). \u6d77\u91cf\u65e5\u5fd7\u6570\u636e\uff0c\u63d0\u53d6\u51fa\u67d0\u65e5\u8bbf\u95ee\u767e\u5ea6\u6b21\u6570\u6700\u591a\u7684\u90a3\u4e2aIP\u3002<\/p>\n
IP\u7684\u6570\u76ee\u8fd8\u662f\u6709\u9650\u7684\uff0c\u6700\u591a2^32\u4e2a\uff0c\u6240\u4ee5\u53ef\u4ee5\u8003\u8651\u4f7f\u7528hash\u5c06ip\u76f4\u63a5\u5b58 \u5165\u5185\u5b58\uff0c\u7136\u540e\u8fdb\u884c\u7edf\u8ba1\u3002<\/p>\n
3.bit-map<\/p>\n
\u9002\u7528\u8303\u56f4\uff1a\u53ef\u8fdb\u884c\u6570\u636e\u7684\u5feb\u901f\u67e5\u627e\uff0c\u5224\u91cd\uff0c\u5220\u9664\uff0c\u4e00\u822c\u6765\u8bf4\u6570\u636e\u8303\u56f4\u662fint \u768410\u500d\u4ee5\u4e0b<\/p>\n
\u57fa\u672c\u539f\u7406\u53ca\u8981\u70b9\uff1a\u4f7f\u7528bit\u6570\u7ec4\u6765\u8868\u793a\u67d0\u4e9b\u5143\u7d20\u662f\u5426\u5b58\u5728\uff0c\u6bd4\u59828\u4f4d\u7535\u8bdd\u53f7\u7801<\/p>\n
\u6269\u5c55\uff1abloom filter\u53ef\u4ee5\u770b\u505a\u662f\u5bf9bit-map\u7684\u6269\u5c55<\/p>\n
\u95ee\u9898\u5b9e\u4f8b\uff1a<\/p>\n
1)\u5df2\u77e5\u67d0\u4e2a\u6587\u4ef6\u5185\u5305\u542b\u4e00\u4e9b\u7535\u8bdd\u53f7\u7801\uff0c\u6bcf\u4e2a\u53f7\u7801\u4e3a8\u4f4d\u6570 \u5b57\uff0c\u7edf\u8ba1\u4e0d\u540c\u53f7\u7801\u7684\u4e2a\u6570\u3002<\/p>\n
8\u4f4d\u6700\u591a99 999 999\uff0c\u5927\u6982\u9700\u898199m\u4e2abit\uff0c\u5927\u698210\u51e0m\u5b57\u8282\u7684\u5185\u5b58\u5373\u53ef\u3002<\/p>\n
2)2.5 \u4ebf\u4e2a\u6574\u6570\u4e2d\u627e\u51fa\u4e0d\u91cd\u590d\u7684\u6574\u6570\u7684\u4e2a\u6570\uff0c\u5185\u5b58\u7a7a\u95f4\u4e0d\u8db3\u4ee5\u5bb9\u7eb3\u8fd92.5\u4ebf\u4e2a\u6574\u6570\u3002<\/p>\n
\u5c06bit-map\u6269\u5c55\u4e00\u4e0b\uff0c\u75282bit\u8868\u793a\u4e00\u4e2a\u6570\u5373\u53ef\uff0c0\u8868\u793a\u672a\u51fa\u73b0\uff0c1\u8868\u793a\u51fa\u73b0\u4e00\u6b21\uff0c2\u8868\u793a\u51fa\u73b02\u6b21\u53ca\u4ee5\u4e0a\u3002\u6216\u8005\u6211\u4eec\u4e0d\u75282bit\u6765\u8fdb\u884c\u8868\u793a\uff0c\u6211\u4eec\u7528\u4e24\u4e2abit-map\u5373\u53ef\u6a21\u62df\u5b9e\u73b0\u8fd9\u4e2a2bit-map\u3002<\/p>\n
4. \u5806<\/p>\n
\u9002\u7528\u8303\u56f4\uff1a\u6d77\u91cf\u6570\u636e\u524dn\u5927\uff0c\u5e76\u4e14n\u6bd4\u8f83\u5c0f\uff0c\u5806\u53ef\u4ee5\u653e\u5165\u5185\u5b58<\/p>\n
\u57fa\u672c\u539f\u7406\u53ca\u8981\u70b9\uff1a\u6700\u5927\u5806\u6c42\u524dn\u5c0f\uff0c\u6700\u5c0f\u5806\u6c42\u524dn\u5927\u3002\u65b9\u6cd5\uff0c\u6bd4\u5982\u6c42\u524dn\u5c0f\uff0c\u6211\u4eec\u6bd4\u8f83\u5f53\u524d\u5143\u7d20\u4e0e\u6700\u5927\u5806\u91cc\u7684\u6700\u5927\u5143\u7d20\uff0c\u5982\u679c\u5b83\u5c0f\u4e8e\u6700\u5927\u5143\u7d20\uff0c\u5219\u5e94\u8be5\u66ff\u6362\u90a3\u4e2a\u6700\u5927\u5143\u7d20\u3002\u8fd9\u6837\u6700\u540e\u5f97\u5230\u7684n\u4e2a\u5143\u7d20\u5c31\u662f\u6700\u5c0f\u7684n\u4e2a\u3002\u9002\u5408\u5927\u6570\u636e\u91cf\uff0c\u6c42\u524dn\u5c0f\uff0cn\u7684\u5927\u5c0f\u6bd4\u8f83\u5c0f\u7684\u60c5\u51b5\uff0c\u8fd9\u6837\u53ef\u4ee5\u626b\u63cf\u4e00\u904d\u5373\u53ef\u5f97\u5230\u6240\u6709\u7684\u524dn\u5143\u7d20\uff0c\u6548\u7387\u5f88\u9ad8\u3002<\/p>\n
\u6269\u5c55\uff1a\u53cc\u5806\uff0c\u4e00\u4e2a\u6700\u5927\u5806\u4e0e\u4e00\u4e2a\u6700\u5c0f\u5806\u7ed3 \u5408\uff0c\u53ef\u4ee5\u7528\u6765\u7ef4\u62a4\u4e2d\u4f4d\u6570\u3002<\/p>\n
\u95ee\u9898\u5b9e\u4f8b\uff1a
1)100w\u4e2a\u6570\u4e2d\u627e\u6700\u5927\u7684\u524d100\u4e2a\u6570\u3002<\/p>\n
\u7528\u4e00\u4e2a100\u4e2a\u5143\u7d20\u5927\u5c0f\u7684 \u6700\u5c0f\u5806\u5373\u53ef\u3002<\/p>\n
5.\u53cc\u5c42\u6876\u5212\u5206<\/p>\n
\u9002\u7528\u8303\u56f4\uff1a\u7b2ck\u5927\uff0c\u4e2d\u4f4d\u6570\uff0c\u4e0d\u91cd\u590d\u6216\u91cd\u590d\u7684\u6570\u5b57<\/p>\n
\u57fa\u672c\u539f\u7406\u53ca\u8981\u70b9\uff1a\u56e0\u4e3a\u5143\u7d20\u8303\u56f4\u5f88\u5927\uff0c\u4e0d\u80fd\u5229\u7528\u76f4\u63a5\u5bfb\u5740\u8868\uff0c\u6240\u4ee5\u901a\u8fc7\u591a\u6b21\u5212\u5206\uff0c\u9010\u6b65\u786e\u5b9a\u8303\u56f4\uff0c\u7136\u540e\u6700\u540e\u5728\u4e00\u4e2a\u53ef\u4ee5\u63a5\u53d7\u7684\u8303\u56f4\u5185\u8fdb\u884c\u3002\u53ef\u4ee5\u901a\u8fc7\u591a\u6b21\u7f29\u5c0f\uff0c\u53cc\u5c42\u53ea\u662f\u4e00\u4e2a\u4f8b\u5b50\u3002<\/p>\n
\u6269 \u5c55\uff1a<\/p>\n
\u95ee\u9898\u5b9e\u4f8b\uff1a
1).2.5\u4ebf\u4e2a\u6574\u6570\u4e2d\u627e\u51fa\u4e0d\u91cd\u590d\u7684\u6574\u6570\u7684\u4e2a\u6570\uff0c\u5185\u5b58\u7a7a\u95f4\u4e0d\u8db3\u4ee5\u5bb9\u7eb3\u8fd92.5\u4ebf\u4e2a\u6574\u6570\u3002<\/p>\n
\u6709\u70b9\u50cf\u9e3d\u5de2\u539f\u7406\uff0c\u6574\u6570\u4e2a\u6570\u4e3a2^32,\u4e5f\u5c31\u662f\uff0c\u6211\u4eec\u53ef\u4ee5\u5c06\u8fd92^32\u4e2a\u6570\uff0c\u5212\u5206\u4e3a2^8\u4e2a\u533a\u57df(\u6bd4\u5982\u7528\u5355\u4e2a\u6587\u4ef6\u4ee3\u8868\u4e00\u4e2a\u533a\u57df)\uff0c\u7136\u540e\u5c06\u6570\u636e\u5206\u79bb\u5230\u4e0d\u540c\u7684\u533a\u57df\uff0c\u7136\u540e\u4e0d\u540c\u7684\u533a\u57df\u5728\u5229\u7528bitmap\u5c31\u53ef\u4ee5\u76f4\u63a5\u89e3\u51b3\u4e86\u3002\u4e5f\u5c31\u662f\u8bf4\u53ea\u8981\u6709\u8db3\u591f\u7684\u78c1\u76d8\u7a7a\u95f4\uff0c\u5c31\u53ef\u4ee5\u5f88\u65b9\u4fbf\u7684\u89e3\u51b3\u3002<\/p>\n
2).5\u4ebf\u4e2aint\u627e\u5b83 \u4eec\u7684\u4e2d\u4f4d\u6570\u3002<\/p>\n
\u8fd9\u4e2a\u4f8b\u5b50\u6bd4\u4e0a\u9762\u90a3\u4e2a\u66f4\u660e\u663e\u3002\u9996\u5148\u6211\u4eec\u5c06int\u5212\u5206\u4e3a2^16\u4e2a\u533a\u57df\uff0c\u7136\u540e\u8bfb\u53d6\u6570\u636e\u7edf\u8ba1\u843d\u5230\u5404\u4e2a\u533a\u57df\u91cc\u7684\u6570\u7684\u4e2a\u6570\uff0c\u4e4b\u540e\u6211\u4eec\u6839\u636e\u7edf\u8ba1\u7ed3\u679c\u5c31\u53ef\u4ee5\u5224\u65ad\u4e2d\u4f4d\u6570\u843d\u5230\u90a3\u4e2a\u533a\u57df\uff0c\u540c\u65f6\u77e5\u9053\u8fd9\u4e2a\u533a\u57df\u4e2d\u7684\u7b2c\u51e0\u5927\u6570\u521a\u597d\u662f\u4e2d\u4f4d\u6570\u3002\u7136\u540e\u7b2c\u4e8c\u6b21\u626b\u63cf\u6211\u4eec\u53ea\u7edf\u8ba1\u843d\u5728\u8fd9\u4e2a\u533a\u57df\u4e2d\u7684\u90a3\u4e9b\u6570\u5c31\u53ef\u4ee5\u4e86\u3002<\/p>\n
\u5b9e\u9645\u4e0a\uff0c\u5982\u679c\u4e0d\u662fint\u662fint64\uff0c\u6211\u4eec\u53ef\u4ee5\u7ecf\u8fc73\u6b21\u8fd9\u6837\u7684\u5212\u5206\u5373\u53ef\u964d\u4f4e\u5230\u53ef\u4ee5\u63a5\u53d7\u7684\u7a0b\u5ea6\u3002\u5373\u53ef\u4ee5\u5148\u5c06int64\u5206\u62102^24\u4e2a\u533a\u57df\uff0c\u7136\u540e\u786e\u5b9a\u533a\u57df\u7684\u7b2c\u51e0\u5927\u6570\uff0c\u5728\u5c06\u8be5\u533a\u57df\u5206\u62102^20\u4e2a\u5b50\u533a\u57df\uff0c\u7136\u540e\u786e\u5b9a\u662f\u5b50\u533a\u57df\u7684\u7b2c\u51e0\u5927\u6570\uff0c\u7136\u540e\u5b50\u533a\u57df\u91cc\u7684\u6570\u7684\u4e2a\u6570\u53ea\u67092^20\uff0c\u5c31\u53ef\u4ee5\u76f4\u63a5\u5229\u7528direct addr table\u8fdb\u884c\u7edf\u8ba1\u4e86\u3002<\/p>\n
6.\u6570\u636e\u5e93\u7d22\u5f15<\/p>\n
\u9002\u7528\u8303\u56f4\uff1a\u5927\u6570\u636e\u91cf\u7684\u589e\u5220\u6539\u67e5<\/p>\n
\u57fa\u672c\u539f\u7406\u53ca\u8981\u70b9\uff1a\u5229\u7528\u6570\u636e\u7684 \u8bbe\u8ba1\u5b9e\u73b0\u65b9\u6cd5\uff0c\u5bf9\u6d77\u91cf\u6570\u636e\u7684\u589e\u5220\u6539\u67e5\u8fdb\u884c\u5904\u7406\u3002
\u6269\u5c55\uff1a
\u95ee\u9898\u5b9e\u4f8b\uff1a<\/p>\n
7.\u5012\u6392\u7d22\u5f15(Inverted index)<\/p>\n
\u9002\u7528\u8303\u56f4\uff1a\u641c\u7d22\u5f15\u64ce\uff0c\u5173\u952e\u5b57\u67e5\u8be2<\/p>\n
\u57fa\u672c\u539f\u7406\u53ca\u8981\u70b9\uff1a\u4e3a\u4f55\u53eb\u5012\u6392\u7d22\u5f15\uff1f\u4e00\u79cd\u7d22\u5f15\u65b9\u6cd5\uff0c\u88ab\u7528\u6765\u5b58\u50a8\u5728\u5168\u6587\u641c\u7d22 \u4e0b\u67d0\u4e2a\u5355\u8bcd\u5728\u4e00\u4e2a\u6587\u6863\u6216\u8005\u4e00\u7ec4\u6587\u6863\u4e2d\u7684\u5b58\u50a8\u4f4d\u7f6e\u7684\u6620\u5c04\u3002<\/p>\n
\u4ee5\u82f1\u6587\u4e3a\u4f8b\uff0c\u4e0b\u9762\u662f\u8981\u88ab\u7d22\u5f15\u7684\u6587\u672c\uff1a \u6b63\u5411\u7d22\u5f15\u5f00\u53d1\u51fa\u6765\u7528\u6765\u5b58\u50a8\u6bcf\u4e2a\u6587\u6863\u7684\u5355\u8bcd\u7684\u5217\u8868\u3002\u6b63\u5411\u7d22\u5f15\u7684\u67e5\u8be2\u5f80\u5f80\u6ee1\u8db3\u6bcf\u4e2a\u6587\u6863\u6709\u5e8f\u9891\u7e41\u7684\u5168\u6587\u67e5\u8be2\u548c\u6bcf\u4e2a\u5355\u8bcd\u5728\u6821\u9a8c\u6587\u6863\u4e2d\u7684\u9a8c\u8bc1\u8fd9\u6837\u7684\u67e5\u8be2\u3002\u5728\u6b63\u5411\u7d22\u5f15\u4e2d\uff0c\u6587\u6863\u5360\u636e\u4e86\u4e2d\u5fc3\u7684\u4f4d\u7f6e\uff0c\u6bcf\u4e2a\u6587\u6863\u6307\u5411\u4e86\u4e00\u4e2a\u5b83\u6240\u5305\u542b\u7684\u7d22\u5f15\u9879\u7684\u5e8f\u5217\u3002\u4e5f\u5c31\u662f\u8bf4\u6587\u6863\u6307\u5411\u4e86\u5b83\u5305\u542b\u7684\u90a3\u4e9b\u5355\u8bcd\uff0c\u800c\u53cd\u5411\u7d22\u5f15\u5219\u662f\u5355\u8bcd\u6307\u5411\u4e86\u5305\u542b\u5b83\u7684\u6587\u6863\uff0c\u5f88\u5bb9\u6613\u770b\u5230\u8fd9\u4e2a\u53cd\u5411\u7684\u5173\u7cfb\u3002<\/p>\n \u6269\u5c55\uff1a<\/p>\n \u95ee\u9898\u5b9e\u4f8b\uff1a\u6587\u6863\u68c0\u7d22\u7cfb\u7edf\uff0c\u67e5\u8be2\u90a3\u4e9b\u6587\u4ef6\u5305\u542b\u4e86 \u67d0\u5355\u8bcd\uff0c\u6bd4\u5982\u5e38\u89c1\u7684\u5b66\u672f\u8bba\u6587\u7684\u5173\u952e\u5b57\u641c\u7d22\u3002<\/p>\n 8.\u5916\u6392\u5e8f<\/p>\n \u9002\u7528\u8303\u56f4\uff1a\u5927\u6570\u636e\u7684\u6392\u5e8f\uff0c\u53bb\u91cd<\/p>\n \u57fa\u672c\u539f\u7406\u53ca\u8981 \u70b9\uff1a\u5916\u6392\u5e8f\u7684\u5f52\u5e76\u65b9\u6cd5\uff0c\u7f6e\u6362\u9009\u62e9 \u8d25\u8005\u6811\u539f\u7406\uff0c\u6700\u4f18\u5f52\u5e76\u6811<\/p>\n \u6269\u5c55\uff1a<\/p>\n \u95ee\u9898\u5b9e\u4f8b\uff1a \u8fd9\u4e2a\u6570\u636e\u5177\u6709\u5f88\u660e\u663e\u7684\u7279\u70b9\uff0c\u8bcd\u7684\u5927\u5c0f\u4e3a16\u4e2a\u5b57\u8282\uff0c\u4f46\u662f\u5185\u5b58\u53ea\u67091m\u505ahash\u6709\u4e9b\u4e0d\u591f\uff0c\u6240\u4ee5\u53ef\u4ee5\u7528\u6765\u6392\u5e8f\u3002\u5185\u5b58\u53ef\u4ee5\u5f53\u8f93\u5165\u7f13\u51b2\u533a\u4f7f\u7528\u3002<\/p>\n 9.trie\u6811<\/p>\n \u9002 \u7528\u8303\u56f4\uff1a\u6570\u636e\u91cf\u5927\uff0c\u91cd\u590d\u591a\uff0c\u4f46\u662f\u6570\u636e\u79cd\u7c7b\u5c0f\u53ef\u4ee5\u653e\u5165\u5185\u5b58<\/p>\n \u57fa\u672c\u539f\u7406\u53ca\u8981\u70b9\uff1a\u5b9e\u73b0\u65b9\u5f0f\uff0c\u8282\u70b9\u5b69\u5b50\u7684\u8868\u793a\u65b9\u5f0f<\/p>\n \u6269\u5c55\uff1a\u538b\u7f29\u5b9e \u73b0\u3002<\/p>\n \u95ee\u9898\u5b9e\u4f8b\uff1a 2).1000\u4e07\u5b57 \u7b26\u4e32\uff0c\u5176\u4e2d\u6709\u4e9b\u662f\u76f8\u540c\u7684(\u91cd\u590d),\u9700\u8981\u628a\u91cd\u590d\u7684\u5168\u90e8\u53bb\u6389\uff0c\u4fdd\u7559\u6ca1\u6709\u91cd\u590d\u7684\u5b57\u7b26\u4e32\u3002\u8bf7\u95ee\u600e\u4e48\u8bbe\u8ba1\u548c\u5b9e\u73b0\uff1f<\/p>\n 3).\u5bfb\u627e\u70ed\u95e8\u67e5\u8be2\uff1a\u67e5\u8be2\u4e32\u7684\u91cd \u590d\u5ea6\u6bd4\u8f83\u9ad8\uff0c\u867d\u7136\u603b\u6570\u662f1\u5343\u4e07\uff0c\u4f46\u5982\u679c\u9664\u53bb\u91cd\u590d\u540e\uff0c\u4e0d\u8d85\u8fc73\u767e\u4e07\u4e2a\uff0c\u6bcf\u4e2a\u4e0d\u8d85\u8fc7255\u5b57\u8282\u3002<\/p>\n 10.\u5206\u5e03\u5f0f\u5904\u7406 mapreduce<\/p>\n \u9002 \u7528\u8303\u56f4\uff1a\u6570\u636e\u91cf\u5927\uff0c\u4f46\u662f\u6570\u636e\u79cd\u7c7b\u5c0f\u53ef\u4ee5\u653e\u5165\u5185\u5b58<\/p>\n \u57fa\u672c\u539f\u7406\u53ca\u8981\u70b9\uff1a\u5c06\u6570\u636e\u4ea4\u7ed9\u4e0d\u540c\u7684\u673a\u5668\u53bb\u5904\u7406\uff0c\u6570\u636e\u5212\u5206\uff0c\u7ed3\u679c\u5f52\u7ea6\u3002<\/p>\n \u6269 \u5c55\uff1a<\/p>\n \u95ee\u9898\u5b9e\u4f8b\uff1a<\/p>\n 1).The canonical example application of MapReduce is a process to count the appearances of<\/p>\n each different word in a set of documents: void reduce(String word, Iterator partialCounts): the Map function, using the word as the result key. The framework puts together all the pairs<\/p>\n with the same key and feeds them to the same call to Reduce, thus this function just needs to<\/p>\n sum all of its input values to find the total appearances of that word.<\/p>\n 2). \u6d77\u91cf\u6570\u636e\u5206\u5e03\u5728100\u53f0\u7535\u8111\u4e2d\uff0c\u60f3\u4e2a\u529e\u6cd5\u9ad8\u6548\u7edf\u8ba1\u51fa\u8fd9\u6279\u6570\u636e\u7684TOP10\u3002<\/p>\n 3).\u4e00\u5171\u6709N\u4e2a\u673a\u5668\uff0c\u6bcf\u4e2a\u673a\u5668\u4e0a\u6709N\u4e2a\u6570\u3002\u6bcf\u4e2a\u673a\u5668\u6700\u591a\u5b58 O(N)\u4e2a\u6570\u5e76\u5bf9\u5b83\u4eec\u64cd\u4f5c\u3002\u5982\u4f55\u627e\u5230N^2\u4e2a\u6570\u7684\u4e2d\u6570(median)\uff1f<\/p>\n \u7ecf\u5178\u95ee\u9898\u5206\u6790<\/p>\n \u4e0a\u5343\u4e07or\u4ebf\u6570\u636e\uff08\u6709 \u91cd\u590d\uff09\uff0c\u7edf\u8ba1\u5176\u4e2d\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u524dN\u4e2a\u6570\u636e,\u5206\u4e24\u79cd\u60c5\u51b5\uff1a\u53ef\u4e00\u6b21\u8bfb\u5165\u5185\u5b58\uff0c\u4e0d\u53ef\u4e00\u6b21\u8bfb\u5165\u3002<\/p>\n \u53ef\u7528\u601d\u8def\uff1atrie\u6811+\u5806\uff0c\u6570\u636e\u5e93\u7d22\u5f15\uff0c\u5212\u5206 \u5b50\u96c6\u5206\u522b\u7edf\u8ba1\uff0chash\uff0c\u5206\u5e03\u5f0f\u8ba1\u7b97\uff0c\u8fd1\u4f3c\u7edf\u8ba1\uff0c\u5916\u6392\u5e8f<\/p>\n \u6240\u8c13\u7684\u662f\u5426\u80fd\u4e00\u6b21\u8bfb\u5165\u5185\u5b58\uff0c\u5b9e\u9645\u4e0a\u5e94\u8be5\u6307\u53bb\u9664\u91cd\u590d\u540e\u7684\u6570\u636e\u91cf\u3002\u5982\u679c\u53bb\u91cd\u540e\u6570\u636e\u53ef \u4ee5\u653e\u5165\u5185\u5b58\uff0c\u6211\u4eec\u53ef\u4ee5\u4e3a\u6570\u636e\u5efa\u7acb\u5b57\u5178\uff0c\u6bd4\u5982\u901a\u8fc7 map\uff0chashmap\uff0ctrie\uff0c\u7136\u540e\u76f4\u63a5\u8fdb\u884c\u7edf\u8ba1\u5373\u53ef\u3002\u5f53\u7136\u5728\u66f4\u65b0\u6bcf\u6761\u6570\u636e\u7684\u51fa\u73b0\u6b21\u6570\u7684\u65f6\u5019\uff0c\u6211\u4eec\u53ef\u4ee5\u5229\u7528\u4e00\u4e2a\u5806\u6765\u7ef4\u62a4\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u524dN\u4e2a\u6570\u636e\uff0c\u5f53\u7136\u8fd9\u6837\u5bfc\u81f4\u7ef4\u62a4\u6b21\u6570\u589e\u52a0\uff0c\u4e0d\u5982\u5b8c\u5168\u7edf\u8ba1\u540e\u5728\u6c42\u524dN\u5927\u6548\u7387\u9ad8\u3002<\/p>\n \u5982\u679c\u6570\u636e\u65e0\u6cd5\u653e\u5165\u5185\u5b58\u3002\u4e00\u65b9\u9762\u6211\u4eec\u53ef\u4ee5\u8003\u8651\u4e0a\u9762\u7684\u5b57\u5178\u65b9\u6cd5\u80fd\u5426\u88ab\u6539\u8fdb\u4ee5\u9002\u5e94\u8fd9\u79cd\u60c5\u5f62\uff0c\u53ef\u4ee5\u505a\u7684\u6539\u53d8\u5c31\u662f\u5c06\u5b57\u5178\u5b58\u653e\u5230\u786c\u76d8\u4e0a\uff0c\u800c\u4e0d\u662f\u5185\u5b58\uff0c\u8fd9\u53ef\u4ee5\u53c2\u8003\u6570\u636e\u5e93\u7684\u5b58\u50a8\u65b9\u6cd5\u3002<\/p>\n \u5f53\u7136\u8fd8\u6709\u66f4\u597d\u7684\u65b9\u6cd5\uff0c\u5c31\u662f\u53ef\u4ee5\u91c7\u7528\u5206\u5e03\u5f0f\u8ba1\u7b97\uff0c\u57fa\u672c\u4e0a\u5c31\u662fmap-reduce\u8fc7\u7a0b\uff0c\u9996\u5148\u53ef\u4ee5\u6839\u636e\u6570\u636e\u503c\u6216\u8005\u628a\u6570\u636ehash(md5)\u540e\u7684\u503c\uff0c\u5c06\u6570\u636e\u6309\u7167\u8303\u56f4\u5212\u5206\u5230\u4e0d\u540c\u7684\u673a\u5b50\uff0c\u6700\u597d\u53ef\u4ee5\u8ba9\u6570\u636e\u5212\u5206\u540e\u53ef\u4ee5\u4e00\u6b21\u8bfb\u5165\u5185\u5b58\uff0c\u8fd9\u6837\u4e0d\u540c\u7684\u673a\u5b50\u8d1f\u8d23\u5904\u7406\u5404\u79cd\u7684\u6570\u503c\u8303\u56f4\uff0c\u5b9e\u9645\u4e0a\u5c31\u662fmap\u3002\u5f97\u5230\u7ed3\u679c\u540e\uff0c\u5404\u4e2a\u673a\u5b50\u53ea\u9700\u62ff\u51fa\u5404\u81ea\u7684\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u524dN\u4e2a\u6570\u636e\uff0c\u7136\u540e\u6c47\u603b\uff0c\u9009\u51fa\u6240\u6709\u7684\u6570\u636e\u4e2d\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u524dN\u4e2a\u6570\u636e\uff0c\u8fd9\u5b9e\u9645\u4e0a\u5c31\u662freduce\u8fc7\u7a0b\u3002<\/p>\n \u5b9e\u9645\u4e0a\u53ef\u80fd\u60f3\u76f4\u63a5\u5c06\u6570\u636e\u5747\u5206\u5230\u4e0d\u540c\u7684\u673a\u5b50\u4e0a\u8fdb\u884c\u5904\u7406\uff0c\u8fd9\u6837\u662f\u65e0\u6cd5\u5f97\u5230\u6b63\u786e\u7684\u89e3\u7684\u3002\u56e0\u4e3a\u4e00\u4e2a\u6570\u636e\u53ef\u80fd\u88ab\u5747\u5206\u5230\u4e0d\u540c\u7684\u673a\u5b50\u4e0a\uff0c\u800c\u53e6\u4e00\u4e2a\u5219\u53ef\u80fd\u5b8c\u5168\u805a\u96c6\u5230\u4e00\u4e2a\u673a\u5b50\u4e0a\uff0c\u540c\u65f6\u8fd8\u53ef\u80fd\u5b58\u5728\u5177\u6709\u76f8\u540c\u6570\u76ee\u7684\u6570\u636e\u3002\u6bd4\u5982\u6211\u4eec\u8981\u627e\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u524d100\u4e2a\uff0c\u6211\u4eec\u5c061000\u4e07\u7684\u6570\u636e\u5206\u5e03\u523010\u53f0\u673a\u5668\u4e0a\uff0c\u627e\u5230\u6bcf\u53f0\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u524d 100\u4e2a\uff0c\u5f52\u5e76\u4e4b\u540e\u8fd9\u6837\u4e0d\u80fd\u4fdd\u8bc1\u627e\u5230\u771f\u6b63\u7684\u7b2c100\u4e2a\uff0c\u56e0\u4e3a\u6bd4\u5982\u51fa\u73b0\u6b21\u6570\u6700\u591a\u7684\u7b2c100\u4e2a\u53ef\u80fd\u67091\u4e07\u4e2a\uff0c\u4f46\u662f\u5b83\u88ab\u5206\u5230\u4e8610\u53f0\u673a\u5b50\uff0c\u8fd9\u6837\u5728\u6bcf\u53f0\u4e0a\u53ea\u67091\u5343\u4e2a\uff0c\u5047\u8bbe\u8fd9\u4e9b\u673a\u5b50\u6392\u540d\u57281000\u4e2a\u4e4b\u524d\u7684\u90a3\u4e9b\u90fd\u662f\u5355\u72ec\u5206\u5e03\u5728\u4e00\u53f0\u673a\u5b50\u4e0a\u7684\uff0c\u6bd4\u5982\u67091001\u4e2a\uff0c\u8fd9\u6837\u672c\u6765\u5177\u67091\u4e07\u4e2a\u7684\u8fd9\u4e2a\u5c31\u4f1a\u88ab\u6dd8\u6c70\uff0c\u5373\u4f7f\u6211\u4eec\u8ba9\u6bcf\u53f0\u673a\u5b50\u9009\u51fa\u51fa\u73b0\u6b21\u6570\u6700\u591a\u76841000\u4e2a\u518d\u5f52\u5e76\uff0c\u4ecd\u7136\u4f1a\u51fa\u9519\uff0c\u56e0\u4e3a\u53ef\u80fd\u5b58\u5728\u5927\u91cf\u4e2a\u6570\u4e3a1001\u4e2a\u7684\u53d1\u751f\u805a\u96c6\u3002\u56e0\u6b64\u4e0d\u80fd\u5c06\u6570\u636e\u968f\u4fbf\u5747\u5206\u5230\u4e0d\u540c\u673a\u5b50\u4e0a\uff0c\u800c\u662f\u8981\u6839\u636ehash \u540e\u7684\u503c\u5c06\u5b83\u4eec\u6620\u5c04\u5230\u4e0d\u540c\u7684\u673a\u5b50\u4e0a\u5904\u7406\uff0c\u8ba9\u4e0d\u540c\u7684\u673a\u5668\u5904\u7406\u4e00\u4e2a\u6570\u503c\u8303\u56f4\u3002<\/p>\n \u800c\u5916\u6392\u5e8f\u7684\u65b9\u6cd5\u4f1a\u6d88\u8017\u5927\u91cf\u7684IO\uff0c\u6548\u7387\u4e0d\u4f1a\u5f88\u9ad8\u3002\u800c\u4e0a\u9762\u7684\u5206\u5e03\u5f0f\u65b9\u6cd5\uff0c\u4e5f\u53ef\u4ee5\u7528\u4e8e\u5355\u673a\u7248\u672c\uff0c\u4e5f\u5c31\u662f\u5c06\u603b\u7684\u6570\u636e\u6839\u636e\u503c\u7684\u8303\u56f4\uff0c\u5212\u5206\u6210\u591a\u4e2a\u4e0d\u540c\u7684\u5b50\u6587\u4ef6\uff0c\u7136\u540e\u9010\u4e2a\u5904\u7406\u3002\u5904\u7406\u5b8c\u6bd5\u4e4b\u540e\u518d\u5bf9\u8fd9\u4e9b\u5355\u8bcd\u7684\u53ca\u5176\u51fa\u73b0\u9891\u7387\u8fdb\u884c\u4e00\u4e2a\u5f52\u5e76\u3002\u5b9e\u9645\u4e0a\u5c31\u53ef\u4ee5\u5229\u7528\u4e00\u4e2a\u5916\u6392\u5e8f\u7684\u5f52\u5e76\u8fc7\u7a0b\u3002<\/p>\n \u53e6\u5916\u8fd8\u53ef\u4ee5\u8003\u8651\u8fd1\u4f3c\u8ba1\u7b97\uff0c\u4e5f\u5c31\u662f\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u7ed3\u5408\u81ea\u7136\u8bed\u8a00\u5c5e\u6027\uff0c\u53ea\u5c06\u90a3\u4e9b\u771f\u6b63\u5b9e\u9645\u4e2d\u51fa\u73b0\u6700\u591a\u7684\u90a3\u4e9b\u8bcd\u4f5c\u4e3a\u4e00\u4e2a\u5b57\u5178\uff0c\u4f7f\u5f97\u8fd9\u4e2a\u89c4\u6a21\u53ef\u4ee5\u653e\u5165\u5185\u5b58\u3002<\/wbr> \u5927\u6570\u636e\u91cf\u7684\u95ee\u9898\u662f\u5f88\u591a\u9762\u8bd5\u7b14\u8bd5\u4e2d\u7ecf\u5e38\u51fa\u73b0\u7684\u95ee\u9898\uff0c\u6bd4\u5982baidu google \u817e\u8baf\u8fd9\u6837\u7684\u4e00\u4e9b\u6d89\u53ca\u5230\u6d77\u91cf\u6570\u636e\u7684\u516c\u53f8\u7ecf\u5e38\u4f1a\u95ee\u5230\u3002<\/p>\n \u4e0b\u9762\u7684\u65b9\u6cd5\u662f\u6211\u5bf9\u6d77\u91cf\u6570\u636e\u7684\u5904\u7406\u65b9\u6cd5\u8fdb\u884c\u4e86\u4e00\u4e2a\u4e00\u822c\u6027\u7684\u603b\u7ed3\uff0c\u5f53\u7136\u8fd9\u4e9b\u65b9\u6cd5\u53ef\u80fd\u5e76\u4e0d\u80fd\u5b8c\u5168\u8986\u76d6\u6240\u6709\u7684\u95ee\u9898\uff0c\u4f46\u662f\u8fd9\u6837\u7684\u4e00\u4e9b\u65b9\u6cd5\u4e5f\u57fa\u672c\u53ef\u4ee5\u5904\u7406\u7edd\u5927\u591a\u6570\u9047\u5230\u7684\u95ee\u9898\u3002\u4e0b\u9762\u7684\u4e00\u4e9b\u95ee\u9898\u57fa\u672c\u76f4\u63a5\u6765\u6e90\u4e8e\u516c\u53f8\u7684\u9762\u8bd5\u7b14\u8bd5\u9898\u76ee\uff0c\u65b9\u6cd5\u4e0d\u4e00\u5b9a\u6700\u4f18\uff0c\u5982\u679c\u4f60\u6709\u66f4\u597d\u7684\u5904\u7406\u65b9\u6cd5\uff0c\u6b22\u8fce\u4e0e\u6211\u8ba8\u8bba\u3002<\/p>\n 1.Bloom filter<\/p>\n \u9002\u7528\u8303\u56f4\uff1a\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u6570\u636e\u5b57\u5178\uff0c\u8fdb\u884c\u6570\u636e\u7684\u5224\u91cd\uff0c\u6216\u8005\u96c6\u5408\u6c42\u4ea4\u96c6<\/p>\n \u57fa\u672c\u539f\u7406\u53ca\u8981\u70b9\uff1a \u8fd8\u6709\u4e00\u4e2a\u6bd4\u8f83\u91cd\u8981\u7684\u95ee\u9898\uff0c\u5982\u4f55\u6839\u636e\u8f93\u5165\u5143\u7d20\u4e2a\u6570n\uff0c\u786e\u5b9a\u4f4d\u6570\u7ec4m\u7684\u5927\u5c0f\u53cahash\u51fd\u6570\u4e2a\u6570\u3002\u5f53hash\u51fd\u6570\u4e2a\u6570k=(ln2)*(m\/n...<\/p>\n
T0 = "it is what it is"
T1 = "what is it"
T2 = "it is a banana"
\u6211\u4eec\u5c31\u80fd\u5f97\u5230\u4e0b\u9762 \u7684\u53cd\u5411\u6587\u4ef6\u7d22\u5f15\uff1a
"a":
"banana": {2}
"is":
"it":
"what":
\u68c0\u7d22\u7684\u6761\u4ef6"what", "is" \u548c "it" \u5c06\u5bf9\u5e94\u96c6\u5408\u7684\u4ea4\u96c6\u3002<\/p>\n
1).\u6709\u4e00\u4e2a1G\u5927\u5c0f\u7684\u4e00\u4e2a\u6587\u4ef6\uff0c\u91cc\u9762\u6bcf\u4e00\u884c\u662f\u4e00\u4e2a\u8bcd\uff0c\u8bcd\u7684\u5927\u5c0f\u4e0d\u8d85\u8fc716\u4e2a\u5b57\u8282\uff0c\u5185\u5b58\u9650\u5236\u5927\u5c0f\u662f1M\u3002\u8fd4\u56de\u9891\u6570\u6700\u9ad8\u7684100\u4e2a\u8bcd\u3002<\/p>\n
1).\u670910\u4e2a\u6587\u4ef6\uff0c\u6bcf\u4e2a\u6587\u4ef61G\uff0c\u6bcf\u4e2a\u6587\u4ef6\u7684\u6bcf\u4e00\u884c\u90fd\u5b58\u653e\u7684\u662f\u7528\u6237\u7684query\uff0c\u6bcf\u4e2a\u6587\u4ef6\u7684query\u90fd\u53ef\u80fd\u91cd\u590d\u3002\u8981\u4f60\u6309\u7167query\u7684\u9891\u5ea6\u6392\u5e8f \u3002<\/p>\n
void map(String name, String document):
\/\/ name: document name
\/\/ document: document contents
for each word w in document:
EmitIntermediate(w, 1);<\/p>\n
\/\/ key: a word
\/\/ values: a list of aggregated partial counts
int result = 0;
for each v in partialCounts:
result += ParseInt(v);
Emit(result);
Here, each document is split in words, and each word is counted initially with a "1" value by<\/p>\n
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr>
\n<\/wbr><\/p>\n","protected":false},"excerpt":{"rendered":"
\u5bf9\u4e8e\u539f\u7406\u6765\u8bf4\u5f88\u7b80\u5355\uff0c\u4f4d\u6570\u7ec4+k\u4e2a\u72ec\u7acbhash\u51fd\u6570\u3002\u5c06hash\u51fd\u6570\u5bf9\u5e94\u7684\u503c\u7684\u4f4d\u6570\u7ec4\u7f6e1\uff0c\u67e5\u627e\u65f6\u5982\u679c\u53d1\u73b0\u6240\u6709hash\u51fd\u6570\u5bf9\u5e94\u4f4d\u90fd\u662f1\u8bf4\u660e\u5b58\u5728\uff0c\u5f88\u660e\u663e\u8fd9\u4e2a\u8fc7\u7a0b\u5e76\u4e0d\u4fdd\u8bc1\u67e5\u627e\u7684\u7ed3\u679c\u662f100%\u6b63\u786e\u7684\u3002\u540c\u65f6\u4e5f\u4e0d\u652f\u6301\u5220\u9664\u4e00\u4e2a\u5df2\u7ecf\u63d2\u5165\u7684\u5173\u952e\u5b57\uff0c\u56e0\u4e3a\u8be5\u5173\u952e\u5b57\u5bf9\u5e94\u7684\u4f4d\u4f1a\u7275\u52a8\u5230\u5176\u4ed6\u7684\u5173\u952e\u5b57\u3002\u6240\u4ee5\u4e00\u4e2a\u7b80\u5355\u7684\u6539\u8fdb\u5c31\u662f counting Bloom filter\uff0c\u7528\u4e00\u4e2acounter\u6570\u7ec4\u4ee3\u66ff\u4f4d\u6570\u7ec4\uff0c\u5c31\u53ef\u4ee5\u652f\u6301\u5220\u9664\u4e86\u3002<\/p>\n