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L\u7684\u6587\u4ef6\u8303\u56f4\u901a\u5e38\u548clevel-(L+1)\u7684\u6587\u4ef6\u8303\u56f4\u662f\u4e0d\u5bf9\u9f50\u7684\uff09\u3002\u538b\u5b9e\u56e0\u6b64\u4f1a\u8bfb\u53d626MB\uff0c\u5199\u516526MB\u3002\u5047\u8bbe\u78c1\u76d8IO\u901f\u5ea6\u4e3a100MB\/s\uff0c\u6700\u5dee\u7684\u538b\u5b9e\u5927\u6982\u6d88\u80170.5s<\/p>\n<p>\u5982\u679c\u6211\u4eec\u51cf\u6162\u540e\u53f0\u5199\u5165\uff0c\u53ea\u53d6\u5168\u901f100MB\/s\u768410%\uff0c\u4e00\u6b21\u538b\u5b9e\u53ef\u80fd\u8017\u65f65s\u3002\u5982\u679c\u7528\u6237\u7684\u5199\u5165\u901f\u5ea6\u4e3a10MB\/s\uff0c\u6211\u4eec\u53ef\u80fd\u521b\u5efa\u8bb8\u591alevel-0\u7684\u6587\u4ef6\uff08\u5927\u69825*10MB\u603b\u517150MB\uff09\u3002\u8fd9\u5c06\u660e\u663e\u7684\u589e\u52a0\u8bfb\u53d6\u6d88\u8017\uff0c\u56e0\u4e3a\u6bcf\u6b21\u8bfb\u53d6\u5408\u5e76\u4e86\u66f4\u591a\u7684\u6587\u4ef6\u589e\u52a0\u4e86\u8d1f\u8f7d\u3002<\/p>\n<p>\u89e3\u51b3\u65b9\u68481\uff1a\u4e3a\u4e86\u51cf\u8f7b\u8fd9\u4e2a\u95ee\u9898\uff0c\u6211\u4eec\u53ef\u80fd\u5e0c\u671b\u5f53level-0\u6587\u4ef6\u6570\u5f88\u5927\u7684\u65f6\u5019\uff0c\u589e\u52a0\u65e5\u5fd7\u5207\u6362\u7684\u9608\u503c\u3002\u867d\u7136\u7f3a\u70b9\u662f\u8fd9\u4e2a\u9608\u503c\u8d8a\u5927\uff0c\u9700\u8981\u8d8a\u591a\u7684\u5185\u5b58\u6765\u4fdd\u5b58\u76f8\u5e94\u7684memtable\u3002<\/p>\n<p>\u89e3\u51b3\u65b9\u68482:\u6211\u4eec\u53ef\u80fd\u5e0c\u671b\u5f53level-0\u7684\u6587\u4ef6\u6570\u53d8\u591a\u65f6\uff0c\u4eba\u4e3a\u589e\u52a0\u5199\u5165\u901f\u5ea6\u3002<\/p>\n<p>\u89e3\u51b3\u65b9\u68483\uff1a\u6211\u4eec\u81f4\u529b\u4e8e\u964d\u4f4e\u5927\u91cf\u6587\u4ef6\u5408\u5e76\u7684\u6210\u672c\u3002\u4e5f\u8bb8\u5927\u591a\u6570level-0\u6587\u4ef6\u5728\u7f13\u5b58\u4e2d\u90fd\u6709\u672a\u538b\u7f29\u7684\u5757\uff0c\u6211\u4eec\u4ec5\u4ec5\u9700\u8981\u62c5\u5fc3O(N)\u590d\u6742\u5ea6\u7684\u5408\u5e76\u8fed\u4ee3\u3002<\/p>\n<h3>4.2 \u6587\u4ef6\u7684\u6570\u91cf<\/h3>\n<p>\u9664\u4e86\u603b\u662f\u751f\u62102MB\u7684\u6587\u4ef6\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u4e3a\u66f4\u9ad8\u7684\u7b49\u7ea7\u751f\u6210\u66f4\u5927\u7684\u6587\u4ef6\uff0c\u4ee5\u6b64\u51cf\u5c11\u6587\u4ef6\u7684\u603b\u6570\uff0c\u867d\u7136\u4ee3\u4ef7\u662f\u66f4\u591a\u7a81\u53d1\u7684\u538b\u7f29\u3002\u5f53\u7136\uff0c\u6211\u4eec\u4e5f\u53ef\u4ee5\u5c06\u6587\u4ef6\u96c6\u5408\u5206\u7247\u653e\u5728\u4e0d\u540c\u7684\u6587\u4ef6\u5939\u4e2d\u3002<\/p>\n<p>\u57282011\u5e742\u67084\u65e5\uff0c\u5728ex3\u6587\u4ef6\u7cfb\u7edf\u4e0a\u505a\u4e86\u4e00\u6b21\u6d4b\u8bd5\uff0c\u8be5\u6d4b\u8bd5\u663e\u793a\uff0c\u5728\u5f88\u591a\u6587\u4ef6\u7684\u76ee\u5f55\u4e2d\u505a100K\u6b21\u6587\u4ef6\u6253\u5f00\u7684\u5e73\u5747\u7528\u65f6\u5982\u4e0b\uff1a<\/p>\n<table>\n<thead>\n<tr>\n<th align=\"right\">Files in directory<\/th>\n<th align=\"right\">Microseconds to open a file<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td align=\"right\">1000<\/td>\n<td align=\"right\">9<\/td>\n<\/tr>\n<tr>\n<td align=\"right\">10000<\/td>\n<td align=\"right\">10<\/td>\n<\/tr>\n<tr>\n<td align=\"right\">100000<\/td>\n<td align=\"right\">16<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u56e0\u6b64\uff0c\u5728\u73b0\u4ee3\u6587\u4ef6\u7cfb\u7edf\u4e2d\uff0c\u4e5f\u8bb8\u8fde\u5206\u7247\u4e5f\u662f\u4e0d\u9700\u8981\u7684\u3002<\/p>\n<h2>5.\u6062\u590d<\/h2>\n<ul>\n<li>\u8bfb\u53d6CURRENT\u53bb\u627e\u5230\u6700\u540e\u4e00\u6b21\u63d0\u4ea4\u7684MANIFEST\u6587\u4ef6\u540d<\/li>\n<li>\u8bfb\u53d6\u8be5MANIFEST\u6587\u4ef6<\/li>\n<li>\u6e05\u9664\u8fc7\u671f\u7684\u6587\u4ef6<\/li>\n<li>\u6211\u4eec\u53ef\u4ee5\u5728\u8fd9\u91cc\u6253\u5f00\u6240\u6709\u7684sstables\uff0c\u4f46\u662f\u61d2\u52a0\u8f7d\u53ef\u80fd\u4f1a\u66f4\u597d\u3002<\/li>\n<li>\u5c06log\u5757\u8f6c\u6362\u6210\u65b0\u7684level-0 sstable<\/li>\n<li>\u5f00\u59cb\u5c06\u6062\u590d\u7684\u5e8f\u5217\u5bfc\u5411\u5230\u65b0\u7684\u65e5\u5fd7\u6587\u4ef6\u7684\u65b0\u7684\u5199\u5165\u6d41\u3002<\/li>\n<\/ul>\n<h2>6.\u6587\u4ef6\u7684\u5783\u573e\u56de\u6536<\/h2>\n<p>\u6bcf\u6b21\u6062\u590d\u7684\u6700\u540e\u4ee5\u53ca\u6bcf\u6b21\u538b\u7f29\u7684\u6700\u540e<code>DeleteObsoleteFiles()<\/code>\u4f1a\u88ab\u8c03\u7528\u3002\u5b83\u4f1a\u627e\u51fa\u6570\u636e\u5e93\u4e2d\u6240\u6709\u7684\u6587\u4ef6\u7684\u540d\u5b57\u3002\u7136\u540e\u5220\u9664\u6240\u6709\u7684\u4e0d\u662f\u5f53\u524d\u65e5\u5fd7\u6587\u4ef6\u7684\u65e5\u5fd7\u6587\u4ef6\u3002\u518d\u5220\u9664\u6240\u6709\u7684\u4e0d\u6d89\u53ca\u5230\u67d0\u4e9blevel\u548c\u4e0d\u662f\u4e00\u4e2a\u6d3b\u8dc3\u7684\u538b\u7f29\u8f93\u51fa\u7684\u8868\u6587\u4ef6\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u8fd9\u90e8\u5206\u662f\u6765\u81ea\u4e8eleveldb\u7684impl.md\u6587\u6863\uff0c\u8be6\u7ec6\u4ecb\u7ecd\u4e86leveldb\u5b9e\u73b0\u65b9\u9762\u7684\u8bbe\u8ba1\u3002 1\u3001\u6587\u4ef6 leve &hellip; <a href=\"https:\/\/www.myway5.com\/index.php\/2017\/07\/17\/leveldb\/\" class=\"more-link\">\u7ee7\u7eed\u9605\u8bfb<span class=\"screen-reader-text\">leveldb\u6587\u6863\u7ffb\u8bd1(2)-leveldb\u7684\u5b9e\u73b0<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,23],"tags":[24],"class_list":["post-161","post","type-post","status-publish","format-standard","hentry","category-cplusplus","category-leveldb","tag-leveldb"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v25.4 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>leveldb\u6587\u6863\u7ffb\u8bd1(2)-leveldb\u7684\u5b9e\u73b0 - \u4e00\u53ea\u5b89\u9759\u7684\u732b<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.myway5.com\/index.php\/2017\/07\/17\/leveldb\/\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"leveldb\u6587\u6863\u7ffb\u8bd1(2)-leveldb\u7684\u5b9e\u73b0 - \u4e00\u53ea\u5b89\u9759\u7684\u732b\" \/>\n<meta property=\"og:description\" content=\"\u8fd9\u90e8\u5206\u662f\u6765\u81ea\u4e8eleveldb\u7684impl.md\u6587\u6863\uff0c\u8be6\u7ec6\u4ecb\u7ecd\u4e86leveldb\u5b9e\u73b0\u65b9\u9762\u7684\u8bbe\u8ba1\u3002 1\u3001\u6587\u4ef6 leve &hellip; \u7ee7\u7eed\u9605\u8bfbleveldb\u6587\u6863\u7ffb\u8bd1(2)-leveldb\u7684\u5b9e\u73b0\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.myway5.com\/index.php\/2017\/07\/17\/leveldb\/\" \/>\n<meta property=\"og:site_name\" content=\"\u4e00\u53ea\u5b89\u9759\u7684\u732b\" \/>\n<meta property=\"article:published_time\" content=\"2017-07-17T15:41:57+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2023-07-05T14:01:05+00:00\" \/>\n<meta name=\"author\" content=\"jiangpengfei\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"jiangpengfei\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 \u5206\" \/>\n<script type=\"application\/ld+json\" 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