{"id":200312,"date":"2025-05-06T12:13:52","date_gmt":"2025-05-06T04:13:52","guid":{"rendered":"https:\/\/server.hk\/cnblog\/200312\/"},"modified":"2025-05-06T12:13:52","modified_gmt":"2025-05-06T04:13:52","slug":"block-nested-loop-join-%e7%ae%97%e6%b3%95%e5%a6%82%e4%bd%95%e4%bc%98%e5%8c%96-nested-loop-join-%e7%ae%97%e6%b3%95%e7%9a%84%e6%89%ab%e6%8f%8f%e6%ac%a1%e6%95%b0%ef%bc%9f","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/200312\/","title":{"rendered":"Block Nested-Loop Join \u7b97\u6cd5\u5982\u4f55\u4f18\u5316 Nested-Loop Join \u7b97\u6cd5\u7684\u626b\u63cf\u6b21\u6570\uff1f"},"content":{"rendered":"

<\/b> <\/p>\n

Block Nested-Loop Join \u7b97\u6cd5\u5982\u4f55\u4f18\u5316 Nested-Loop Join \u7b97\u6cd5\u7684\u626b\u63cf\u6b21\u6570\uff1f<\/h1>\n

\u6570\u636e\u5e93\u5c0f\u767d\u4e00\u679a\uff0c\u6b63\u5728\u4e0d\u65ad\u5b66\u4e60\u79ef\u7d2f\u77e5\u8bc6\uff0c\u73b0\u5c06\u5b66\u4e60\u5230\u7684\u77e5\u8bc6\u8bb0\u5f55\u4e00\u4e0b\uff0c\u4e5f\u662f\u5c06\u6211\u7684\u6240\u5f97\u5206\u4eab\u7ed9\u5927\u5bb6\uff01\u800c\u4eca\u5929\u8fd9\u7bc7\u6587\u7ae0\u300aBlock Nested-Loop Join \u7b97\u6cd5\u5982\u4f55\u4f18\u5316 Nested-Loop Join \u7b97\u6cd5\u7684\u626b\u63cf\u6b21\u6570\uff1f\u300b\u5e26\u5927\u5bb6\u6765\u4e86\u89e3\u4e00\u4e0b##content_title##\uff0c\u5e0c\u671b\u5bf9\u5927\u5bb6\u7684\u77e5\u8bc6\u79ef\u7d2f\u6709\u6240\u5e2e\u52a9\uff0c\u4ece\u800c\u5f25\u8865\u81ea\u5df1\u7684\u4e0d\u8db3\uff0c\u52a9\u529b\u5b9e\u6218\u5f00\u53d1\uff01<\/p>\n

<\/p>\n

<\/p>\n

Block Nested-Loop Join\u7b97\u6cd5\u4f18\u5316\u539f\u7406\u5256\u6790<\/strong><\/p>\n

Block Nested-Loop Join (BNL) \u7b97\u6cd5\u9488\u5bf9 Nested-Loop Join (NLJ) \u7b97\u6cd5\u7684\u626b\u63cf\u6b21\u6570\u8fc7\u591a\u95ee\u9898\u8fdb\u884c\u4e86\u4f18\u5316\u3002BNL \u7b97\u6cd5\u7684\u5de5\u4f5c\u539f\u7406\u5982\u4e0b\uff1a<\/p>\n

\u5c06\u5916\u5c42\u5faa\u73af\u7684\u7ed3\u679c\u96c6\u4ee5\u6570\u636e\u5757\u7684\u5f62\u5f0f\u4fdd\u5b58\u5728 Join Buffer \u4e2d\u3002\u5f53\u5185\u5c42\u8868\u626b\u63cf\u6bcf\u4e00\u884c\u65f6\uff0c\u4ec5\u9700\u4e0e\u5176 Join Buffer \u4e2d\u7684\u6570\u636e\u5757\u8fdb\u884c\u6bd4\u8f83\uff0c\u800c\u4e0d\u662f\u6bcf\u6b21\u5b8c\u6574\u626b\u63cf\u5916\u5c42\u8868\u3002<\/p>\n

\u4e3e\u4e2a\u4f8b\u5b50\uff1a<\/strong><\/p>\n

\u5047\u8bbe\u5916\u5c42\u8868\u6709 1000 \u884c\uff0c\u5185\u5c42\u8868\u6709 1000 \u884c\u3002\u4f7f\u7528 NLJ \u7b97\u6cd5\uff0c\u5185\u5c42\u8868\u9700\u8981\u8fdb\u884c 1000 \u6b21\u626b\u63cf\u3002\u4f46\u4f7f\u7528 BNL \u7b97\u6cd5\uff0c\u5982\u679c Join Buffer \u5927\u5c0f\u4e3a 100 \u884c\uff0c\u5219\u5185\u5c42\u8868\u4ec5\u9700\u8fdb\u884c 10 \u6b21\u626b\u63cf\uff0c\u56e0\u4e3a\u53ea\u9700\u4e0e Join Buffer \u4e2d\u7684 100 \u884c\u8fdb\u884c\u6bd4\u8f83\u5373\u53ef\u3002<\/p>\n

\u201c\u53ef\u4ee5\u4e00\u6b21\u6027\u4e0e 100 \u884c\u6570\u636e\u8fdb\u884c\u6bd4\u8f83\u201d\u7684\u542b\u4e49<\/strong><\/p>\n

\u4e0e NLJ \u7b97\u6cd5\u76f8\u6bd4\uff0cBNL \u7b97\u6cd5\u7684\u4f18\u52bf\u5728\u4e8e\u6279\u91cf\u6bd4\u8f83\u3002\u7b80\u5355\u5730\u8bf4\uff0c\u5185\u5c42\u8868\u7684\u6bcf\u4e00\u884c\u4e0e Join Buffer \u4e2d\u7684\u5168\u90e8 100 \u884c\u6570\u636e\u8fdb\u884c\u4e00\u6b21\u6027\u6bd4\u8f83\u3002<\/p>\n

\u8fd9\u907f\u514d\u4e86 NLJ \u7b97\u6cd5\u4e2d\u91cd\u590d\u626b\u63cf\u5185\u5c42\u8868\u7684\u5f00\u9500\uff0c\u56e0\u4e3a\u53ea\u9700\u626b\u63cf\u4e00\u6b21\u5373\u53ef\u4e0e\u6240\u6709\u5339\u914d\u7684\u5916\u5c42\u8868\u884c\u8fdb\u884c\u6bd4\u8f83\u3002\u56e0\u6b64\uff0cBNL \u7b97\u6cd5\u53ef\u4ee5\u663e\u8457\u51cf\u5c11\u626b\u63cf\u6b21\u6570\uff0c\u63d0\u9ad8\u67e5\u8be2\u6027\u80fd\u3002<\/p>\n

\u7ec8\u4e8e\u4ecb\u7ecd\u5b8c\u5566\uff01\u5c0f\u4f19\u4f34\u4eec\uff0c\u8fd9\u7bc7\u5173\u4e8e\u300aBlock Nested-Loop Join \u7b97\u6cd5\u5982\u4f55\u4f18\u5316 Nested-Loop Join \u7b97\u6cd5\u7684\u626b\u63cf\u6b21\u6570\uff1f\u300b\u7684\u4ecb\u7ecd\u5e94\u8be5\u8ba9\u4f60\u6536\u83b7\u591a\u591a\u4e86\u5427\uff01\u6b22\u8fce\u5927\u5bb6\u6536\u85cf\u6216\u5206\u4eab\u7ed9\u66f4\u591a\u9700\u8981\u5b66\u4e60\u7684\u670b\u53cb\u5427~\u4e3b\u673a\u5b9d\u8d1d\u516c\u4f17\u53f7\u4e5f\u4f1a\u53d1\u5e03\u6570\u636e\u5e93\u76f8\u5173\u77e5\u8bc6\uff0c\u5feb\u6765\u5173\u6ce8\u5427\uff01<\/p>\n

\n
\n <\/dt>\n<\/dl>\n","protected":false},"excerpt":{"rendered":"

Block Nested-Loo...<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-200312","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200312","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=200312"}],"version-history":[{"count":0,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/200312\/revisions"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=200312"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=200312"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=200312"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}