{"id":3001,"date":"2019-03-28T19:47:09","date_gmt":"2019-03-28T11:47:09","guid":{"rendered":"https:\/\/damogame.cn:15443\/wordpress\/?p=3001"},"modified":"2019-03-28T19:47:09","modified_gmt":"2019-03-28T11:47:09","slug":"leveldb%e7%9a%84%e4%b8%80%e4%ba%9b%e7%ae%80%e5%8d%95%e6%80%bb%e7%bb%93","status":"publish","type":"post","link":"https:\/\/i007.cc\/wordpress\/archives\/3001","title":{"rendered":"LevelDB\u7684\u4e00\u4e9b\u7b80\u5355\u603b\u7ed3"},"content":{"rendered":"
\n
\n
<\/div>\n<\/div>\n<\/div>\n
\n
\n
LevelDB\u7279\u70b9<\/div>\n
\n
    \n
  1. key value\u8bb0\u5f55\u6301\u4e45\u5316\u5b58\u50a8\uff0c\u8bb0\u5f55\u53ef\u538b\u7f29<\/li>\n
  2. \u652f\u6301\u9ad8\u5199\u5165\u7684\u573a\u5408<\/li>\n
  3. \u5177\u6709\u63d2\u5165Put\uff0c\u5220\u9664Delete\uff0c\u4ee5\u53ca\u8bfb\u53d6Get\u8bb0\u5f55\u4e09\u79cd\u57fa\u672c\u64cd\u4f5c\u3002\u4e0d\u5305\u542b\u66f4\u65b0\u64cd\u4f5c\uff0c\u53ef\u4ee5\u76f4\u63a5\u63d2\u5165\u65b0\u7684value\u8868\u793a\u66f4\u65b0\u3002\u652f\u6301\u6279\u91cf\u5199\u5165\uff0c\u5229\u7528WriteBatch\u5c06\u591a\u4e2a\u5199\u64cd\u4f5c\u5408\u5e76\u5230\u4e00\u8d77<\/li>\n
  4. \u9ed8\u8ba4\u5199\u5165\u4e3a\u5f02\u6b65\u5199\u5165\uff0c\u901f\u5ea6\u5feb\uff0c\u5148\u5199\u5165\u65e5\u5fd7\u518d\u5199\u5165\u5185\u5b58\uff0c\u540c\u6b65\u5199\u5165\u6781\u6162\u3002<\/li>\n
  5. \u652f\u6301\u5feb\u7167\u64cd\u4f5c\u3002\u53ef\u901a\u8fc7\u5feb\u7167\u4fdd\u6301\u8bfb\u53d6\u6570\u636e\u7684\u4e00\u81f4\u6027\uff0c\u4e0d\u53d7\u5230\u4e2d\u95f4\u5199\u5165\u8fc7\u7a0b\u7684\u5f71\u54cd<\/li>\n
  6. \u5355\u8fdb\u7a0b\u591a\u7ebf\u7a0b\u64cd\u4f5c\u4e00\u4e2a\u5e93\u662f\u5b89\u5168\u7684\uff0c\u591a\u8fdb\u7a0b\u662f\u9700\u8981\u7528\u6237\u81ea\u5df1\u7ba1\u7406\u5e76\u53d1\u7684\u3002<\/li>\n
  7. \u4ec5\u4ec5\u662f\u4e00\u4e2a\u5e93\u800c\u5df2\uff0c\u6ca1\u6709\u81ea\u5df1\u7684\u670d\u52a1\u8fdb\u7a0b<\/li>\n<\/ol>\n

    <\/a>Level\u5b58\u50a8\u7ed3\u6784<\/h1>\n

    <\/a>1\uff0c\u5185\u5b58\u7684\u6570\u636e<\/h2>\n

    \u5185\u5b58\u4e2d\u6709\u4e24\u4e2a\u8868MemTable\u548cImmutable MemTable
    \nMemTable\u4ee3\u8868\u5f53\u524d\u6d3b\u8dc3\u7684\u8868\uff0c\u5b83\u4e3b\u8981\u5305\u542bLog\uff0c Manifest\uff0c\u4ee5\u53caCurrent\u4e09\u4e2a\u786c\u76d8\u6587\u4ef6\uff0c\u4ee5\u53ca\u5185\u5b58\u4e2d\u7684\u4e00\u4e2a\u8df3\u8868SkipList\u3002
    \nLog\u662f\u7528\u6765\u8bb0\u5f55\u7528\u6237\u7684\u5199\u5165\u6216\u8005\u5220\u9664\u64cd\u4f5c\uff0c\u5148\u5199\u5165log\u6587\u4ef6(\u6309\u64cd\u4f5c\u7684\u987a\u5e8f)\uff0c\u518d\u5199\u5165MemTable\u7684SkipList\u4e2d(\u6839\u636ekey\u6709\u5e8f\u63d2\u5165\u5230\u76f8\u5e94\u7684\u8df3\u8868\u4f4d\u7f6e)\u3002<\/p>\n

    \u5f53MemTable\u7684\u5bb9\u91cf\u8fbe\u5230\u4e00\u5b9a\u7a0b\u5e8f\u540e\uff0c\u6b64Memtable\u88ab\u8f6c\u6362\u4e3aImmutable MemTable\uff0c\u4ecd\u7136\u5728\u5185\u5b58\u4e2d\uff0c\u4f46\u53ef\u8bfb\u4e0d\u53ef\u5199\u3002\u65b0\u7684MemTable\u88ab\u521b\u5efa\uff0c\u5e76\u7528\u6765\u670d\u52a1\u65b0\u7684\u5199\u5165\u8bf7\u6c42\uff0c\u81f3\u4e8eImmutable MemTable\u4ec0\u4e48\u65f6\u5019\u4f1a\u88ab\u5199\u5165\u5230\u786c\u76d8\u4e2d\uff0c\u53ef\u53c2\u89c1\u6570\u636e\u7684\u5408\u5e76\u4e2dsimple compaction\u64cd\u4f5c\u3002<\/p>\n

    <\/a>2\uff0c\u786c\u76d8\u4e2d\u7684\u6570\u636e<\/h2>\n

    \u786c\u76d8\u4e2d\u6709\u591a\u7ea7Level\u7684\u6570\u636e\u8868\uff0c\u53eb\u505aSSTable
    \n\u5b83\u4eceLevel 0 \u5230Level N\uff0c\u6bcf\u4e00\u4e2a\u7ea7\u522b\u90fd\u53ef\u80fd\u6709\u591a\u4e2asst\u6570\u636e\u8868\u3002
    \nLevel 1\u5230Level N\uff1a<\/strong>\u00a0\u5b83\u4eec\u7684\u6bcf\u7ea7\u5185\u90e8\u7684\u6570\u636e\u8868\u4e4b\u95f4\u7684key\u662f\u65e0\u4ea4\u53c9\u7684(\u5177\u4f53\u53c2\u89c1\u6570\u636e\u7684\u5408\u5e76)\u3002
    \nLevel 0\uff1a<\/strong>\u00a0Level 0\u6bd4\u8f83\u7279\u522b\uff0c\u5b83\u7684\u591a\u4e2a\u6570\u636e\u8868\u7684key\u6709\u4ea4\u53c9\u3002Level 0\u7684\u6bcf\u4e00\u4e2a\u6570\u636e\u8868\u90fd\u662f\u76f4\u63a5\u6765\u6e90\u4e8eImmutable MemTable\uff0c\u5f53\u7cfb\u7edf\u8fdb\u884c\u8bb0\u5f55\u7684\u7b80\u5355\u5408\u5e76\u64cd\u4f5c\u65f6\u5019\uff0c\u76f4\u63a5\u5c06Immutable MemTable\u4e2d\u7684\u8df3\u8868\u8f6c\u6362\u4e3a\u4e00\u4e2asst\uff0c\u56e0\u6b64Level 0\u4e2d\u7684\u591a\u4e2asst\u7684key\u53ef\u80fd\u6709\u4ea4\u53c9\u3002<\/p>\n

    <\/a>\u77e5\u8bc6\u70b9<\/h1>\n

    <\/a>\u6570\u636e\u7684\u5408\u5e76Compaction<\/h2>\n

    \u5f53\u9700\u8981\u5220\u9664\u6570\u636e\u65f6\u5019\uff0c\u7cfb\u7edf\u76f4\u63a5\u63d2\u5165\u5220\u9664\u6807\u8bb0\u5373\u53ef\uff0c\u90a3\u65e7\u7684\u6570\u636e\u4ec0\u4e48\u65f6\u5019\u624d\u4f1a\u88ab\u6e05\u9664\u5462\uff1f\u8fd9\u5c31\u8981\u7528\u5230Compaction\u64cd\u4f5c\u3002\u6709\u4e24\u79cd\u5408\u5e76\uff0c\u4e00\u79cd\u662fsimple\uff0c\u4e00\u79cd\u662fmajor\u3002
    \nsimple compaction\u64cd\u4f5c\u5c31\u662fImmutable MemTable\u4e2d\u7684\u8df3\u8868\u8f6c\u6362\u4e3aLevel 0\u7684\u4e00\u4e2asst(\u5185\u5b58\u5230\u786c\u76d8)\u3002
    \nmajor compaction\u64cd\u4f5c\u6307\u7684\u662fLevel L\u4e0eLevel L+1\u7684\u5408\u5e76\u64cd\u4f5c\uff0c\u662f\u5c42\u7ea7\u4e4b\u95f4\u7684\u5408\u5e76\u64cd\u4f5c(\u786c\u76d8\u5230\u786c\u76d8)\u3002\u5f53L >=1\u7684\u65f6\u5019\uff0c\u9996\u5148\u9009\u53d6Level L\u4e2d\u7684\u4e00\u4e2a\u6570\u636e\u8868\uff0c\u7136\u540e\u5bfb\u627eLevel L+1\u4e2d\u7684\u6240\u6709\u4e0eLevel L\u7684key\u6709\u4ea4\u53c9\u7684\u6570\u636e\u8868\uff0c\u8fdb\u884c\u591a\u8def\u5408\u5e76\u3002\u5408\u5e76\u7684\u4e00\u4e2a\u539f\u5219\u5c31\u662f\uff0c\u5982\u679cLevel L\u4e2d\u6709\u4e00\u4e2akey\u5728Level L+1\u4e2d\u5b58\u5728\uff0c\u90a3\u4e48\u5c06Level L+1\u4e2d\u7684\u6240\u6709\u8fd9\u6837\u7684key\u8bb0\u5f55\u90fd\u5220\u9664\u5373\u53ef\u3002\u5f53L = 0\uff0c\u5b83\u548cLevel 1\u7684\u5408\u5e76\u6709\u4e9b\u7279\u6b8a\uff0c\u6211\u4eec\u9700\u8981\u9009\u53d6Level 0\u7684\u591a\u4e2a\u6570\u636e\u8868(\u7531\u4e8eLevel 0\u7684key\u662f\u6709\u4ea4\u53c9\u7684)\uff0c\u4e0eLevel 1\u7684\u591a\u4e2a\u6570\u636e\u8868\u8fdb\u884c\u5408\u5e76\u3002<\/p>\n

    <\/a>SSTable\u6570\u636e\u8868\u7684\u7ed3\u6784<\/h2>\n

    \u6570\u636e\u8868\u6709\u591a\u4e2a\u6570\u636e\u5757\uff0c\u5b58\u50a8\u6709Block\u7684\u7d22\u5f15\uff0c\u4ee5\u53ca\u76f8\u5e94Block\u7684\u6570\u636e\u3002Block\u7684\u5927\u5c0f\u4e3a32KB\u3002<\/p>\n

    <\/a>\u7f13\u5b58<\/h2>\n

    \u6709\u4e24\u4e2a\u7ea7\u522b\u7684\u7f13\u5b58\uff0c\u6570\u636e\u8868\u7684\u7d22\u5f15\u7f13\u5b58\uff0c\u6570\u636eBlock\u7684\u7f13\u5b58\u3002\u7d22\u5f15\u7684\u7f13\u5b58\u662f\u9ed8\u8ba4\uff0cBlock\u7684\u7f13\u5b58\u53ef\u914d\u7f6e\u3002<\/p>\n

    <\/a>\u4e3a\u4ec0\u4e48\u5199\u5165\u6027\u80fd\u8f83\u597d\uff1f<\/h2>\n

    \u8df3\u8868\u662f\u5728\u5185\u5b58\u4e2d\uff0c\u5229\u7528\u4e86\u591a\u7ea7\u94fe\u8868\u7684\u7ed3\u6784\uff0c\u67e5\u627e\u548c\u63d2\u5165\u6548\u7387\u9ad8\uff0c\u6bd4\u5e73\u8861\u6811\u51cf\u5c11\u4e86\u5f88\u591a\u8282\u70b9\u79fb\u52a8\u7684\u64cd\u4f5c\uff0c\u56e0\u6b64\u63d2\u5165\u901f\u5ea6\u6781\u5feb\uff1b\u65e5\u5fd7\u7684\u5199\u5165\u867d\u7136\u662f\u78c1\u76d8\u5199\u5165\uff0c\u4f46\u7531\u4e8e\u662f\u987a\u5e8f\u5199\u5165\uff0c\u56e0\u6b64\u6027\u80fd\u4e5f\u5f88\u597d\u3002<\/p>\n

    <\/a>\u4e3a\u4ec0\u4e48\u8bfb\u53d6\u6bd4\u8f83\u6162\uff1f<\/h2>\n

    \u9996\u5148\u67e5\u627eMemTable\u548cImmutable MemTable\uff0c\u6ca1\u6709\u627e\u5230\u7684\u8bdd\u8fdb\u5165cache\u4e2d\u67e5\u627e\uff0c\u4ecd\u7136\u6ca1\u6709\u627e\u5230\uff0c\u90a3\u4e48\u53ea\u80fd\u901a\u8fc7\u786c\u76d8\u67e5\u627e\u4e86\u3002
    \n\u786c\u76d8\u67e5\u627e\u9996\u5148\u67e5\u627eLevel 0\uff0c\u5982\u679c\u6ca1\u6709\u7ee7\u7eedLevel 1\uff0c\u76f4\u5230\u6700\u540e\u4e00\u5c42Level\uff0c\u8fd8\u6ca1\u627e\u5230\uff0c\u90a3\u4e48\u4e0d\u5b58\u5728\uff0c\u5982\u679c\u4e2d\u95f4\u4efb\u4f55\u4e00\u4e2a\u5730\u65b9\u627e\u5230\u4e86\uff0c\u90a3\u4e48\u76f4\u63a5\u8fd4\u56de\u3002\u8fd9\u4e2a\u987a\u5e8f\u65f6\u6839\u636e\u6570\u636e\u7684\u65b0\u65e7\u987a\u5e8f\u800c\u6765\u7684\u3002 \u5bf9\u4e8e\u67d0\u4e00\u4e2aLevel\u7684\u6570\u636e\u8868\u5177\u4f53\u67e5\u627e\u5982\u4f55\u6267\u884c\u7684\u5462\uff1f \u9996\u5148\u8f7d\u5165\u8fd9\u4e2a\u6570\u636e\u8868\u7684\u7d22\u5f15\u5230\u5185\u5b58\u4e2d\uff0c\u67e5\u770bkey\u4f4d\u4e8e\u54ea\u4e00\u4e2aBlock\u4e2d\uff0c\u7136\u540e\u5c06\u76f8\u5e94\u7684Block\u8f7d\u5165\u5230\u5185\u5b58\u4e2d\uff0c\u9010\u4e2a\u67e5\u627e\u8bb0\u5f55\u3002 \u81f3\u5c11\u9700\u8981\u4e24\u6b21\u786c\u76d8\u8bfb\u53d6\u64cd\u4f5c\uff0c\u5f88\u6162\uff0c\u987a\u5e8f\u8bfb\u56e0\u4e3a\u6709\u7f13\u5b58\u7684\u7f18\u6545\uff0c\u6027\u80fd\u76f8\u5bf9\u8f83\u597d\u3002<\/p>\n

    <\/a>\u5b98\u65b9\u7684\u6027\u80fd\u6570\u636e<\/h1>\n

    \u8fd9\u4e00\u4e2a\u90e8\u5206\u6458\u53d6\u7684\u4e00\u4e2a\u535a\u5ba2\u7684\u5185\u5bb9(\u611f\u8c22\u5176\u6574\u7406\u7ffb\u8bd1):
    \n\u4f5c\u8005\uff1aJeff Dean, Sanjay Ghemawat
    \n\u539f\u6587\uff1a    http:\/\/leveldb.googlecode.com\/svn\/trunk\/doc\/index.html<\/a>
    \n\u8bd1\u8005\uff1aphylips@bmy 2011-8-16
    \n\u8bd1\u6587\uff1a    http:\/\/duanple.blog.163.com\/blog\/static\/70971767201171705113636<\/a><\/p>\n

    <\/a>\u6d4b\u8bd5\u73af\u5883<\/h2>\n

    \u4f7f\u7528\u4e00\u4e2a\u5177\u6709\u767e\u4e07\u6761\u8bb0\u5f55\u7684\u6570\u636e\u5e93\uff0c\u6bcf\u6761\u8bb0\u5f55\u6709\u4e00\u4e2a16\u5b57\u8282\u7684key\u53ca100\u5b57\u8282\u7684value\u3002\u5bf9\u4e8evalues\u503c\u538b\u7f29\u540e\u53ef\u80fd\u5927\u6982\u53ea\u6709\u539f\u59cb\u5927\u5c0f\u7684\u4e00\u534a\u3002
    \nLevelDB: version 1.1
    \nDate: Sun May 1 12:11:26 2011
    \nCPU: 4 x Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz
    \nCPUCache: 4096 KB
    \nKeys: 16 bytes each
    \nValues: 100 bytes each (50 bytes after compression)
    \nEntries: 1000000
    \nRaw Size: 110.6 MB (estimated)
    \nFile Size: 62.9 MB (estimated)<\/p>\n

    <\/a>\u5199\u6027\u80fd<\/h2>\n

    \u201cfill\u201d benchmarks\u4f1a\u4ee5\u987a\u5e8f\u5730\u6216\u8005\u968f\u673a\u7684\u65b9\u5f0f\u521b\u5efa\u4e00\u4e2a\u5168\u65b0\u7684\u6570\u636e\u5e93\u3002\u201dfillsync\u201d benchmark \u7684\u6bcf\u6b21\u64cd\u4f5c\u90fd\u4f1a\u5c06\u6570\u636e\u4ece\u64cd\u4f5c\u7cfb\u7edfflush\u5230\u78c1\u76d8\uff1b\u5176\u4ed6\u7684\u5199\u64cd\u4f5c\u4f1a\u5141\u8bb8\u6570\u636e\u5728\u64cd\u4f5c\u7cfb\u7edfbuffer\u4e2d\u505c\u7559\u4e00\u6bb5\u65f6\u95f4\u3002\u201doverwrite\u201d benchmark \u4f1a\u8fdb\u884c\u968f\u673a\u7684\u5199\u5165\u4ee5\u66f4\u65b0\u6570\u636e\u5e93\u4e2d\u73b0\u6709\u7684key\u503c\u3002
    \nfillseq : 1.765 micros\/op; 62.7 MB\/s
    \nfillsync : 268.409 micros\/op; 0.4 MB\/s (10000 ops)
    \nfillrandom : 2.460 micros\/op; 45.0 MB\/s
    \noverwrite : 2.380 micros\/op; 46.5 MB\/s
    \n\u4e0a\u9762\u7684\u4e00\u6b21\u201dop\u201d\u610f\u5473\u7740\u5bf9\u4e8e\u5355\u4e2akey\/value\u5bf9\u7684\u4e00\u6b21\u5199\u4eba\u3002\u6bd4\u5982\u968f\u673a\u5199benchmark\u6bcf\u79d2\u5927\u6982\u53ef\u4ee5\u8fd1\u4f3c\u8fbe\u5230400,000\u5199\u64cd\u4f5c\u3002
    \n\u6bcf\u4e2a\u201dfillsync\u201d\u64cd\u4f5c\u82b1\u8d39(0.3ms)\u8fdc\u5c0f\u4e8e\u4e00\u6b21\u78c1\u76d8seek\u64cd\u4f5c(\u901a\u5e38\u9700\u898110ms)\u3002\u6211\u4eec\u6000\u7591\u8fd9\u662f\u56e0\u4e3a\u786c\u76d8\u672c\u8eab\u4f1a\u5c06\u8fd9\u4e9b\u66f4\u65b0\u7f13\u5b58\u5230\u5b83\u7684memory\u91cc\uff0c\u5728\u6570\u636e\u771f\u6b63\u5199\u5165\u5230\u6247\u533a\u4e4b\u524d\u5c31\u505a\u51fa\u4e86\u54cd\u5e94\u3002\u8fd9\u79cd\u60c5\u51b5\u4e0b\u7684\u5b89\u5168\u6027\u53d6\u51b3\u4e8e\u786c\u76d8\u5728\u7535\u529b\u4f9b\u5e94\u51fa\u95ee\u9898\u65f6\u662f\u5426\u6709\u8db3\u591f\u7684\u7535\u529b\u53bb\u4fdd\u5b58\u5b83\u7684memory\u4e2d\u7684\u6570\u636e\u3002<\/p>\n

    <\/a>\u8bfb\u6027\u80fd<\/h2>\n

    \u6211\u4eec\u5217\u51fa\u4e86\u6b63\u5411\u53ca\u53cd\u5411\u987a\u5e8f\u8bfb\u7684\u6027\u80fd\uff0c\u4ee5\u53ca\u968f\u673a\u67e5\u627e\u7684\u6027\u80fd\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u7531benchmark\u521b\u5efa\u7684\u6570\u636e\u5e93\u662f\u5f88\u5c0f\u7684\u3002\u56e0\u6b64\u8fd9\u4e2a\u62a5\u544a\u53ea\u662f\u523b\u753b\u4e86\u5de5\u4f5c\u96c6\u53ef\u4ee5\u8f7d\u5165\u5230\u5185\u5b58\u65f6\u7684LevelDB\u7684\u6027\u80fd<\/strong>\u3002\u5bf9\u4e8e\u90a3\u4e9b\u672a\u547d\u4e2d\u64cd\u4f5c\u7cfb\u7edf\u7f13\u5b58\u7684\u5355\u7247\u6570\u636e\u8bfb\u53d6\u64cd\u4f5c\u6765\u8bf4\uff0c\u5f00\u9500\u4e3b\u8981\u662f\u7531\u4e3a\u4ece\u78c1\u76d8\u83b7\u53d6\u6570\u636e\u6240\u9700\u8fdb\u884c\u7684\u4e00\u6b21\u6216\u4e24\u6b21\u78c1\u76d8seek\u64cd\u4f5c\u9020\u6210\u7684\u3002\u800c\u5199\u64cd\u4f5c\u6027\u80fd\u51e0\u4e4e\u4e0d\u53d7\u5de5\u4f5c\u96c6\u80fd\u5426\u8f7d\u5165\u5230\u5185\u5b58\u7684\u5f71\u54cd\u3002
    \nreadrandom : 16.677 micros\/op; (\u6bcf\u79d2\u5927\u698260,000 reads)
    \nreadseq : 0.476 micros\/op; 232.3 MB\/s
    \nreadreverse : 0.724 micros\/op; 152.9 MB\/s
    \nLevelDB\u4e3a\u63d0\u9ad8\u8bfb\u6027\u80fd\u4f1a\u5728\u540e\u53f0\u538b\u7f29\u5b83\u7684\u5e95\u5c42\u5b58\u50a8\u6570\u636e\u3002\u4e0a\u9762\u7684\u6d4b\u8bd5\u662f\u5728\u8fdb\u884c\u8fc7\u5927\u91cf\u7684\u968f\u673a\u5199\u64cd\u4f5c\u4e4b\u540e\u7acb\u5373\u8fdb\u884c\u7684\u3002\u5728\u8fdb\u884c\u8fc7compactions(\u901a\u5e38\u662f\u81ea\u52a8\u89e6\u53d1\u7684)\u518d\u8fdb\u884c\u6d4b\u8bd5\u7ed3\u679c\u4f1a\u66f4\u597d\u4e9b\u3002
    \nreadrandom : 11.602 micros\/op; (\u6bcf\u79d2\u5927\u698285,000 reads)
    \nreadseq : 0.423 micros\/op; 261.8 MB\/s
    \nreadreverse : 0.663 micros\/op; 166.9 MB\/s
    \n\u67d0\u4e9b\u8bfb\u64cd\u4f5c\u7684\u9ad8\u82b1\u8d39\u662f\u7531\u4e8e\u4ece\u786c\u76d8\u8bfb\u53d6\u51fa\u7684blocks\u7684\u91cd\u590d\u89e3\u538b<\/strong>\u5bfc\u81f4\u7684\u3002\u5982\u679c\u6211\u4eec\u53ef\u4ee5\u4e3aLevelDB\u63d0\u4f9b\u8db3\u591f\u7684\u7f13\u5b58\u4f7f\u5f97\u5b83\u53ef\u4ee5\u5c06\u6240\u6709\u7684\u672a\u538b\u7f29\u5757\u653e\u5165\u5185\u5b58<\/strong>\uff0c\u90a3\u4e48\u8bfb\u6027\u80fd\u4f1a\u6709\u66f4\u5927\u5730\u6539\u5584\uff1a
    \nreadrandom : 9.775 micros\/op; (\u6bcf\u79d2\u5927\u6982 100,000 reads before compaction)
    \nreadrandom : 5.215 micros\/op; (\u6bcf\u79d2\u5927\u6982190,000 reads after compaction)<\/p>\n<\/div>\n<\/div>\n<\/article>\n","protected":false},"excerpt":{"rendered":"

    LevelDB\u7279\u70b9 key value\u8bb0<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"colormag_page_container_layout":"default_layout","colormag_page_sidebar_layout":"default_layout","footnotes":""},"categories":[],"tags":[119],"class_list":["post-3001","post","type-post","status-publish","format-standard","hentry","tag-03-"],"_links":{"self":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/3001","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/comments?post=3001"}],"version-history":[{"count":0,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/posts\/3001\/revisions"}],"wp:attachment":[{"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/media?parent=3001"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/categories?post=3001"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/i007.cc\/wordpress\/wp-json\/wp\/v2\/tags?post=3001"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}