{"id":26952,"date":"2024-11-24T09:39:16","date_gmt":"2024-11-24T01:39:16","guid":{"rendered":"https:\/\/fwq.ai\/blog\/26952\/"},"modified":"2024-11-24T09:39:16","modified_gmt":"2024-11-24T01:39:16","slug":"mysql-%e4%b8%ad-key_len-%e7%9a%84%e8%ae%a1%e7%ae%97%e6%96%b9%e6%b3%95%ef%bc%9a%e4%b8%ba%e4%bb%80%e4%b9%88%e5%8f%aa%e6%9c%89-3-%e6%9d%a1%e8%ae%b0%e5%bd%95%e6%97%b6-key_len-%e4%b8%ba-80%ef%bc%9f-2","status":"publish","type":"post","link":"https:\/\/fwq.ai\/blog\/26952\/","title":{"rendered":"MySQL \u4e2d key_len \u7684\u8ba1\u7b97\u65b9\u6cd5\uff1a\u4e3a\u4ec0\u4e48\u53ea\u6709 3 \u6761\u8bb0\u5f55\u65f6 key_len \u4e3a 80\uff1f"},"content":{"rendered":"

\"MySQL<\/p>\n

key_len \u8ba1\u7b97\u65b9\u6cd5<\/strong><\/p>\n

mariadb 8.0 \u5f15\u5165\u4e86 optimizer trace \u6027\u80fd\u5206\u6790\u5de5\u5177\uff0c\u53ef\u4ee5\u901a\u8fc7\u5b83\u67e5\u770b mysql \u7684\u6267\u884c\u8ba1\u5212\u3002\u5728\u4f7f\u7528 expln \u67e5\u8be2\u6267\u884c\u8ba1\u5212\u65f6\uff0c\u6211\u4eec\u53ef\u80fd\u4f1a\u53d1\u73b0 key_len \u7684\u503c\u4e0e\u9884\u671f\u4e0d\u7b26\u3002\u672c\u6587\u5c06\u63a2\u8ba8 mysql \u4e2d key_len \u7684\u8ba1\u7b97\u65b9\u5f0f\uff0c\u5e76\u89e3\u51b3\u4ec5\u6709 3 \u6761\u8bb0\u5f55\u65f6 key_len \u4e3a 80 \u7684\u95ee\u9898\u3002<\/p>\n

key_len \u7684\u542b\u4e49<\/strong><\/p>\n

key_len \u8868\u793a\u7d22\u5f15\u952e\u7684\u957f\u5ea6\u3002\u5bf9\u4e8e\u5b57\u7b26\u7c7b\u578b\uff0ckey_len \u4e3a\u6bcf\u4e2a\u5b57\u7b26\u7684\u5b57\u8282\u6570\u4e58\u4ee5\u7d22\u5f15\u952e\u7684\u957f\u5ea6\u3002<\/p>\n

utf8mb4 \u7f16\u7801<\/strong><\/p>\n

\u95ee\u9898\u4e2d\u7684 student_name \u5217\u4f7f\u7528 utf8mb4 \u5b57\u7b26\u96c6\uff0c\u8be5\u5b57\u7b26\u96c6\u4f7f\u7528\u4e0d\u540c\u6570\u91cf\u7684\u5b57\u8282\u6765\u8868\u793a\u4e0d\u540c\u5b57\u7b26\u3002\u6c49\u5b57\u5b57\u7b26\u9700\u8981 3 \u4e2a\u5b57\u8282\uff0c\u800c\u82f1\u6587\u5b57\u6bcd\u4ec5\u9700\u8981 1 \u4e2a\u5b57\u8282\u3002<\/p>\n

key_len \u8ba1\u7b97<\/strong><\/p>\n

\u5bf9\u4e8e\u95ee\u9898\u4e2d\u7684\u4f8b\u5b50\uff0cstudent_name \u5217\u7684\u957f\u5ea6\u4e3a 20 \u4e2a\u5b57\u7b26\uff0c\u800c\u4e00\u4e2a utf8mb4 \u5b57\u7b26\u4e3a 4 \u4e2a\u5b57\u8282\uff0c\u56e0\u6b64 key_len \u4e3a\uff1a<\/p>\n

key_len = 20 * 4 = 80<\/pre>\n
 \u767b\u5f55\u540e\u590d\u5236 <\/p>\n
\u867d\u7136\u53ea\u6709 3 \u6761\u8bb0\u5f55\uff0c\u4f46 key_len \u4e0d\u53d7\u8bb0\u5f55\u6570\u7684\u5f71\u54cd\u3002\u8fd9\u662f\u56e0\u4e3a\u7d22\u5f15\u952e\u7684\u957f\u5ea6\u662f\u56fa\u5b9a\u7684\uff0c\u5e76\u4e14\u4e0e\u5b58\u50a8\u7684\u6570\u636e\u65e0\u5173\u3002<\/p>\n
\u56e0\u6b64\uff0c\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\uff0ckey_len \u4e3a 80 \u662f\u56e0\u4e3a utf8mb4 \u7f16\u7801\u4f7f\u7528 4 \u4e2a\u5b57\u8282\u8868\u793a\u6bcf\u4e2a\u5b57\u7b26\uff0c\u800c\u7d22\u5f15\u952e\u7684\u957f\u5ea6\u4e3a 20 \u4e2a\u5b57\u7b26\u3002<\/p>\n
\u4ee5\u4e0a\u5c31\u662fMySQL \u4e2d key_len \u7684\u8ba1\u7b97\u65b9\u6cd5\uff1a\u53ea\u6709 3 \u6761\u8bb0\u5f55\u65f6 key_len \u4e3a 80\uff1f\u7684\u8be6\u7ec6\u5185\u5bb9\uff0c\u66f4\u591a\u8bf7\u5173\u6ce8\u7c73\u4e91\u5176\u5b83\u76f8\u5173\u6587\u7ae0\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
key_len \u8ba1\u7b97\u65b9\u6cd5 mariadb 8.0 \u5f15\u5165\u4e86 optimizer trace \u6027\u80fd\u5206\u6790\u5de5\u5177\uff0c\u53ef\u4ee5\u901a\u8fc7\u5b83\u67e5\u770b mysql \u7684\u6267\u884c\u8ba1\u5212\u3002\u5728\u4f7f\u7528 expln \u67e5\u8be2\u6267\u884c\u8ba1\u5212\u65f6\uff0c\u6211\u4eec\u53ef\u80fd\u4f1a\u53d1\u73b0 key_len \u7684\u503c\u4e0e\u9884\u671f\u4e0d\u7b26\u3002\u672c\u6587\u5c06\u63a2\u8ba8 mysql \u4e2d key_len \u7684\u8ba1\u7b97\u65b9\u5f0f\uff0c\u5e76\u89e3\u51b3\u4ec5\u6709 3 \u6761\u8bb0\u5f55\u65f6 key_len \u4e3a 80 \u7684\u95ee\u9898\u3002 key_len \u7684\u542b\u4e49 key_len \u8868\u793a\u7d22\u5f15\u952e\u7684\u957f\u5ea6\u3002\u5bf9\u4e8e\u5b57\u7b26\u7c7b\u578b\uff0ckey_len \u4e3a\u6bcf\u4e2a\u5b57\u7b26\u7684\u5b57\u8282\u6570\u4e58\u4ee5\u7d22\u5f15\u952e\u7684\u957f\u5ea6\u3002 utf8mb4 \u7f16\u7801 \u95ee\u9898\u4e2d\u7684 student_name \u5217\u4f7f\u7528 utf8mb4 \u5b57\u7b26\u96c6\uff0c\u8be5\u5b57\u7b26\u96c6\u4f7f\u7528\u4e0d\u540c\u6570\u91cf\u7684\u5b57\u8282\u6765\u8868\u793a\u4e0d\u540c\u5b57\u7b26\u3002\u6c49\u5b57\u5b57\u7b26\u9700\u8981 3 \u4e2a\u5b57\u8282\uff0c\u800c\u82f1\u6587\u5b57\u6bcd\u4ec5\u9700\u8981 1 \u4e2a\u5b57\u8282\u3002 key_len \u8ba1\u7b97 \u5bf9\u4e8e\u95ee\u9898\u4e2d\u7684\u4f8b\u5b50\uff0cstudent_name \u5217\u7684\u957f\u5ea6\u4e3a 20 \u4e2a\u5b57\u7b26\uff0c\u800c\u4e00\u4e2a utf8mb4 \u5b57\u7b26\u4e3a 4 \u4e2a\u5b57\u8282\uff0c\u56e0\u6b64 key_len \u4e3a\uff1a key_len = 20 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-26952","post","type-post","status-publish","format-standard","hentry","category-16"],"_links":{"self":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/26952","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/comments?post=26952"}],"version-history":[{"count":0,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/posts\/26952\/revisions"}],"wp:attachment":[{"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/media?parent=26952"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/categories?post=26952"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/fwq.ai\/blog\/wp-json\/wp\/v2\/tags?post=26952"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}