{"id":339,"date":"2022-06-24T16:20:57","date_gmt":"2022-06-24T08:20:57","guid":{"rendered":"https:\/\/frogvps.com\/?p=339"},"modified":"2022-06-24T16:20:57","modified_gmt":"2022-06-24T08:20:57","slug":"mysql%e7%b4%a2%e5%bc%95%e5%88%9b%e5%bb%ba%e5%92%8c%e4%bd%bf%e7%94%a8","status":"publish","type":"post","link":"https:\/\/frogvps.com\/?p=339","title":{"rendered":"MYSQL\u7d22\u5f15\u521b\u5efa\u548c\u4f7f\u7528"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">\u7d22\u5f15\u4ecb\u7ecd<\/h2>\n\n\n\n<p>\u7d22\u5f15\u662f\u6392\u5e8f\u7684\uff0c\u7528\u4e8e\u5feb\u901f\u67e5\u627e\u7684\u7279\u6b8a\u6570\u636e\u7ed3\u6784\uff0c\u5b83\u5b9a\u4e49\u5728\u4f5c\u4e3a\u67e5\u627e\u6761\u4ef6\u7684\u5b57\u6bb5\u4e0a\uff0c\u53c8\u53ebkey\uff08\u952e\uff09\uff0c\u7d22\u5f15\u901a\u8fc7\u5b58\u50a8\u5f15\u64ce\u6765\u5b9e\u73b0\u3002InnoDB\u4f7f\u7528B+Tree\u7d22\u5f15\u3002<\/p>\n\n\n\n<p><strong>\u4f18\u70b9\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u7d22\u5f15\u53ef\u4ee5\u964d\u4f4e\u670d\u52a1\u9700\u8981\u626b\u63cf\u7684\u6570\u636e\u91cf\uff0c\u51cf\u5c11\u4e86IO\u6b21\u6570<\/li><li>\u7d22\u5f15\u53ef\u4ee5\u5e2e\u52a9\u670d\u52a1\u5668\u907f\u514d\u6392\u5e8f\u548c\u4f7f\u7528\u4e34\u65f6\u8868<\/li><li>\u7d22\u5f15\u53ef\u4ee5\u5e2e\u52a9\u5c06\u968f\u673aI\/O\u8f6c\u4e3a\u987a\u5e8fI\/O<\/li><\/ul>\n\n\n\n<p><strong>\u7f3a\u70b9\uff1a<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\"><li>\u5360\u7528\u989d\u5916\u7a7a\u95f4\uff0c\u5f71\u54cd\u63d2\u5165\u901f\u5ea6<\/li><\/ul>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">\u7ba1\u7406\u7d22\u5f15<\/h2>\n\n\n\n<p><strong>\u521b\u5efa\u7d22\u5f15\uff1a<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>CREATE &#91;UNIQUE] INDEX index_name ON tbl_name (index_col_name&#91;(length)],...);<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>ALTER TABLE tbl_name ADD INDEX index_name(index_col_name&#91;(length)]);<\/code><\/pre>\n\n\n\n<p><strong>\u8303\u4f8b\uff1a\u4e24\u79cd\u7ed9students\u8868\u683c\u7684name\u5b57\u6bb5\u521b\u5efa\u7d22\u5f15\u7684\u65b9\u6cd5<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>CREATE INDEX idx_name ON students(name);\nALTER TABLE students ADD INDEX idx_name(name);<\/code><\/pre>\n\n\n\n<p><strong>\u5220\u9664\u7d22\u5f15\uff1a<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>DROP INDEX index_name ON tbl_name;<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>ALTER TABLE tbl_name DROP INDEX index_name(index_col_name);<\/code><\/pre>\n\n\n\n<p><strong>\u67e5\u770b\u7d22\u5f15\uff1a<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SHOW INDEX FROM &#91;db_name.]tbl_name;<\/code><\/pre>\n\n\n\n<p><strong>\u4f18\u5316\u8868\u7a7a\u95f4\uff1a<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>OPTIMIZE TABLE tb_name;<\/code><\/pre>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">EXPLAIN \u5de5\u5177<\/h2>\n\n\n\n<p>EXPLAIN\u547d\u4ee4\u53ef\u4ee5\u5206\u6790\u7d22\u5f15\u7684\u6709\u6548\u6027\uff0c\u83b7\u53d6\u67e5\u8be2\u6267\u884c\u8ba1\u5212\u4fe1\u606f\uff0c\u7528\u6765\u67e5\u770b\u67e5\u8be2\u4f18\u5316\u5668\u5982\u4f55\u6267\u884c\u67e5\u8be2\u3002<\/p>\n\n\n\n<p><strong>\u8bed\u6cd5\uff1a<\/strong><\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>EXPLAIN SELECT clause<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"971\" src=\"https:\/\/frogvps.com\/wp-content\/uploads\/2022\/06\/20220624a1-1024x971.jpg\" alt=\"\" class=\"wp-image-341\" srcset=\"https:\/\/frogvps.com\/wp-content\/uploads\/2022\/06\/20220624a1-1024x971.jpg 1024w, https:\/\/frogvps.com\/wp-content\/uploads\/2022\/06\/20220624a1-300x284.jpg 300w, https:\/\/frogvps.com\/wp-content\/uploads\/2022\/06\/20220624a1-768x728.jpg 768w, https:\/\/frogvps.com\/wp-content\/uploads\/2022\/06\/20220624a1.jpg 1036w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><figcaption>explain \u8f93\u51fa\u4fe1\u606f\u8bf4\u660e<\/figcaption><\/figure>\n\n\n\n<p>type\u663e\u793a\u7684\u662f\u8bbf\u95ee\u7c7b\u578b\uff0c\u662f\u8f83\u4e3a\u91cd\u8981\u7684\u4e00\u4e2a\u6307\u6807\uff0c\u7ed3\u679c\u503c\u4ece\u597d\u5230\u574f\u4f9d\u6b21\u662f\uff1a<\/p>\n\n\n\n<p>NULL> system >const > eq_ref > ref > fulltext > ref_or_null > index_merge > unique_subquery > index_subquery > range > index > ALL<\/p>\n\n\n\n<p>\u4e00\u822c\u6765\u8bf4\uff0c\u5f97\u4fdd\u8bc1\u67e5\u8be2\u81f3\u5c11\u8fbe\u5230<strong>range<\/strong>\u7ea7\u522b\uff0c\u6700\u597d\u80fd\u8fbe\u5230<strong>ref<\/strong>\u3002<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1025\" height=\"825\" src=\"https:\/\/frogvps.com\/wp-content\/uploads\/2022\/06\/20220624a2.jpg\" alt=\"\" class=\"wp-image-342\" srcset=\"https:\/\/frogvps.com\/wp-content\/uploads\/2022\/06\/20220624a2.jpg 1025w, https:\/\/frogvps.com\/wp-content\/uploads\/2022\/06\/20220624a2-300x241.jpg 300w, https:\/\/frogvps.com\/wp-content\/uploads\/2022\/06\/20220624a2-768x618.jpg 768w\" sizes=\"auto, (max-width: 1025px) 100vw, 1025px\" \/><figcaption>type \u7c7b\u578b\u8bf4\u660e<\/figcaption><\/figure>\n\n\n\n<hr class=\"wp-block-separator has-alpha-channel-opacity\"\/>\n\n\n\n<h2 class=\"wp-block-heading\">PROFILE \u5de5\u5177<\/h2>\n\n\n\n<p>\u8bbe\u7f6e\u7cfb\u7edf\u53d8\u91cfprofiling\u540e\uff0c\u53ef\u4ee5\u67e5\u770b\u8bed\u53e5\u6267\u884c\u7684\u65f6\u957f\u548c\u8be6\u7ec6\u8fc7\u7a0b\u3002(\u6b64\u529f\u80fd\u5728\u672a\u6765\u7684\u7248\u672c\u4f1a\u88ab\u5f03\u7528)<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SET profiling = ON;<\/code><\/pre>\n\n\n\n<p>\u67e5\u770b\u8bed\u53e5\u6267\u884c\u8fc7\u7a0b<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>SHOW profiles;<\/code><\/pre>\n\n\n\n<p>\u663e\u793a\u67d0\u6761\u8bed\u53e5\u66f4\u8be6\u7ec6\u7684\u6267\u884c\u6b65\u9aa4\uff0c#\u8868\u793a\u8bed\u53e5\u7f16\u53f7<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Show profile for query #;<\/code><\/pre>\n\n\n\n<p>\u663e\u793a\u67d0\u6761\u8bed\u53e5cpu\u7684\u4f7f\u7528\u60c5\u51b5<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code>Show profile cpu for query #;<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u7d22\u5f15\u4ecb\u7ecd \u7d22\u5f15\u662f\u6392\u5e8f\u7684\uff0c\u7528\u4e8e\u5feb\u901f\u67e5\u627e\u7684\u7279\u6b8a\u6570\u636e\u7ed3\u6784\uff0c\u5b83\u5b9a\u4e49\u5728\u4f5c\u4e3a\u67e5\u627e\u6761\u4ef6\u7684\u5b57\u6bb5\u4e0a\uff0c\u53c8\u53ebkey\uff08\u952e\uff09\uff0c\u7d22\u5f15\u901a\u8fc7\u5b58\u50a8\u5f15\u64ce\u6765\u5b9e\u73b0\u3002InnoDB\u4f7f\u7528B+Tree\u7d22\u5f15\u3002 \u4f18\u70b9\uff1a \u7d22\u5f15\u53ef\u4ee5\u964d\u4f4e\u670d\u52a1\u9700\u8981\u626b\u63cf\u7684\u6570\u636e\u91cf\uff0c\u51cf\u5c11\u4e86IO\u6b21\u6570 \u7d22\u5f15\u53ef\u4ee5\u5e2e\u52a9\u670d\u52a1\u5668\u907f\u514d&#8230;<\/p>\n","protected":false},"author":1,"featured_media":283,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35],"tags":[36],"topic":[],"class_list":["post-339","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-35","tag-mysql"],"_links":{"self":[{"href":"https:\/\/frogvps.com\/index.php?rest_route=\/wp\/v2\/posts\/339","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/frogvps.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/frogvps.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/frogvps.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/frogvps.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=339"}],"version-history":[{"count":3,"href":"https:\/\/frogvps.com\/index.php?rest_route=\/wp\/v2\/posts\/339\/revisions"}],"predecessor-version":[{"id":344,"href":"https:\/\/frogvps.com\/index.php?rest_route=\/wp\/v2\/posts\/339\/revisions\/344"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/frogvps.com\/index.php?rest_route=\/wp\/v2\/media\/283"}],"wp:attachment":[{"href":"https:\/\/frogvps.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=339"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/frogvps.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=339"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/frogvps.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=339"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/frogvps.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftopic&post=339"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}