{"id":5378,"date":"2020-07-29T23:59:14","date_gmt":"2020-07-29T15:59:14","guid":{"rendered":"http:\/\/39.97.231.10\/?p=5378"},"modified":"2020-07-29T23:59:14","modified_gmt":"2020-07-29T15:59:14","slug":"mysql-%e4%b8%8d%e5%8f%af%e8%a7%81%e7%b4%a2%e5%bc%95-invisible-indexes","status":"publish","type":"post","link":"http:\/\/www.weijing.co\/?p=5378","title":{"rendered":"MySQL \u4e0d\u53ef\u89c1\u7d22\u5f15 (Invisible Indexes)"},"content":{"rendered":"<div>\n<div>\nMySQL 8.0 \u7248\u672c\u652f\u6301\u4e0d\u53ef\u89c1\u7d22\u5f15\uff08Invisible Indexes\uff09\uff0c\u4e5f\u5c31\u662f\u7d22\u5f15\u5bf9\u4f18\u5316\u5668\u4e0d\u53ef\u89c1\uff0c\u65e0\u6cd5\u4f7f\u7528\u4e0d\u53ef\u89c1\u7d22\u5f15\u5bf9\u67e5\u8be2\u8fdb\u884c\u4f18\u5316\uff0c\u4e0d\u53ef\u89c1\u7d22\u5f15\u4e0d\u9002\u7528\u4e8e\u4e3b\u952e\u3002\n<\/div>\n<\/div>\n<div>\n<div>\n<h5>\u4e00\u3001\u4e0d\u53ef\u89c1\u7d22\u5f15\u7684\u4f7f\u7528\u573a\u666f<\/h5>\n<p>\u5728\u4e00\u5f20\u5927\u8868\u4e0a\u521b\u5efa\u548c\u5220\u9664\u7d22\u5f15\u662f\u6709\u9ad8\u989d\u6210\u672c\u7684\uff0c\u6709\u65f6\u5019\u9700\u8981\u6d4b\u8bd5\u4e00\u4e2a\u7d22\u5f15\u662f\u5426\u6709\u6548\uff0c\u53ef\u4ee5\u4e34\u65f6\u5220\u9664\u7d22\u5f15\uff0c\u5bf9\u6bd4\u7d22\u5f15\u5b58\u5728\u4e0e\u5426\uff0c\u5bf9\u67e5\u8be2\u7684\u6027\u80fd\u5f71\u54cd\u3002\u4f7f\u7528\u7d22\u5f15\u4e0d\u53ef\u89c1\u7684\u7279\u6027\uff0c\u5c31\u80fd\u907f\u514d\u7d22\u5f15\u88ab\u771f\u6b63\u5220\u9664\uff0c\u5728\u9700\u8981\u7684\u65f6\u5019\uff0c\u628a\u7d22\u5f15\u8bbe\u7f6e\u4e3a\u53ef\u89c1\u5373\u53ef\uff0c\u907f\u514d\u4e86\u7d22\u5f15\u771f\u6b63\u5220\u9664\u548c\u521b\u5efa\u5e26\u6765\u7684\u5f71\u54cd\u3002<\/p>\n<h5>\u4e8c\u3001\u4e0d\u53ef\u89c1\u7d22\u5f15\u8bed\u6cd5<\/h5>\n<p>\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c\u7d22\u5f15\u90fd\u662f\u53ef\u89c1\u7684\uff0c\u53ef\u4ee5\u4f7f\u7528\u4e0b\u9762\u7684\u5173\u952e\u5b57\u6765\u6307\u5b9a\u7d22\u5f15\u7684\u53ef\u89c1\u6027\u3002<\/p>\n<ul>\n<li>VISIBLE<\/li>\n<li>INVISIBLE<\/li>\n<\/ul>\n<p>\u5728\u521b\u5efa\u8868\uff0c\u521b\u5efa\u7d22\u5f15\uff0c\u4fee\u6539\u7d22\u5f15\u7684\u8bed\u53e5\u4e2d\uff0c\u4f7f\u7528\u4e0a\u8ff0\u5173\u952e\u5b57\uff0c\u6307\u5b9a\u7d22\u5f15\u7684\u53ef\u89c1\u6027\uff0c\u793a\u4f8b\u5982\u4e0b\uff1a<\/p>\n<pre># \u521b\u5efa\u8868\nCREATE TABLE t1 (\n  i INT,\n  j INT,\n  k INT,\n  INDEX i_idx (i) INVISIBLE\n) ENGINE = InnoDB;\n# \u521b\u5efa\u7d22\u5f15\nCREATE INDEX j_idx ON t1 (j) INVISIBLE;\n# \u589e\u52a0\u7d22\u5f15\nALTER TABLE t1 ADD INDEX k_idx (k) INVISIBLE;\n<\/pre>\n<p>\u5982\u679c\u60f3\u4fee\u6539\u4e00\u4e2a\u7d22\u5f15\u7684\u53ef\u89c1\u6027\uff0c\u4f7f\u7528\u5982\u4e0b\u8bed\u6cd5\uff1a<\/p>\n<pre>ALTER TABLE t1 ALTER INDEX i_idx INVISIBLE;\nALTER TABLE t1 ALTER INDEX i_idx VISIBLE;\n<\/pre>\n<h5>\u4e09\u3001\u67e5\u8be2\u7d22\u5f15\u7684\u53ef\u89c1\u6027<\/h5>\n<p>\u901a\u5e38\u4f7f\u7528 NFORMATION_SCHEMA.STATISTICS \u8868\u6216\u8005 show index from xxx \u8bed\u6cd5\u6765\u67e5\u8be2\u8868\u4e2d\u7d22\u5f15\u7684\u53ef\u89c1\u6027\uff0c\u5982\u4e0b\uff1a<\/p>\n<pre>mysql&gt; SELECT INDEX_NAME, IS_VISIBLE\n       FROM INFORMATION_SCHEMA.STATISTICS\n       WHERE TABLE_SCHEMA = \\'db1\\' AND TABLE_NAME = \\'t1\\';\n+------------+------------+\n| INDEX_NAME | IS_VISIBLE |\n+------------+------------+\n| i_idx      | YES        |\n| j_idx      | NO         |\n| k_idx      | NO         |\n+------------+------------+\nmysql&gt; show index from sbtest1\\\\G\n*************************** 1. row ***************************\n        Table: sbtest1\n   Non_unique: 0\n     Key_name: PRIMARY\n Seq_in_index: 1\n  Column_name: id\n    Collation: A\n  Cardinality: 985302\n     Sub_part: NULL\n       Packed: NULL\n         Null:\n   Index_type: BTREE\n      Comment:\nIndex_comment:\n      Visible: YES\n   Expression: NULL\n*************************** 2. row ***************************\n        Table: sbtest1\n   Non_unique: 1\n     Key_name: k_1\n Seq_in_index: 1\n  Column_name: k\n    Collation: A\n  Cardinality: 158371\n     Sub_part: NULL\n       Packed: NULL\n         Null:\n   Index_type: BTREE\n      Comment:\nIndex_comment:\n      Visible: YES\n   Expression: NULL\n2 rows in set (0.01 sec)\n<\/pre>\n<h5>\u56db\u3001\u4e0d\u53ef\u89c1\u7d22\u5f15\u6ce8\u610f\u4e8b\u9879<\/h5>\n<p>\u5728\u4f18\u5316\u5668\u53c2\u6570 optimizer_switch \u6709\u4e00\u4e2a\u9009\u9879 use_invisible_indexes\u00a0\u6765\u63a7\u5236\u4f18\u5316\u5668\u662f\u5426\u53ef\u4ee5\u4f7f\u7528\u4e0d\u53ef\u89c1\u7d22\u5f15\uff0c\u8be5\u9009\u9879\u9ed8\u8ba4\u4e3a off\uff0c\u5373\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c\u4e0d\u80fd\u4f7f\u7528\u4e0d\u53ef\u89c1\u7d22\u5f15\u3002\u5982\u679c\u8be5\u9009\u9879\u8bbe\u7f6e\u4e3a on\uff0c\u4e0d\u53ef\u89c1\u7d22\u5f15\u4ecd\u7136\u4fdd\u6301\u4e0d\u53ef\u89c1\uff0c\u4f46\u662f\u4f18\u5316\u5668\u5728\u6784\u5efa\u6267\u884c\u8ba1\u5212\u65f6\uff0c\u5c06\u8be5\u7d22\u5f15\u8003\u8651\u5728\u5185\u3002<br \/>\n\u4e0d\u53ef\u89c1\u7d22\u5f15\u4e0d\u5f71\u54cd\u8be5\u7d22\u5f15\u7684\u7ef4\u62a4\uff0c\u6bd4\u5982\u6570\u636e\u66f4\u65b0\uff0c\u4e0d\u53ef\u89c1\u7d22\u5f15\u540c\u6837\u4e5f\u4f1a\u66f4\u65b0\uff0c\u4e0d\u53ef\u89c1\u7684\u552f\u4e00\u7d22\u5f15\uff0c\u540c\u6837\u53ef\u4ee5\u963b\u6b62\u76f8\u540c\u503c\u7684\u63d2\u5165\u3002<br \/>\n\u9690\u5f0f\u7684\u975e\u7a7a\u552f\u4e00\u7d22\u5f15\u4f5c\u4e3a\u8868\u7684\u4e3b\u952e\uff0c\u8be5\u552f\u4e00\u7d22\u5f15\u4e0d\u80fd\u8bbe\u7f6e\u4e3a\u4e0d\u53ef\u89c1\uff0c\u9664\u975e\u6dfb\u52a0\u4e00\u4e2a\u663e\u5f0f\u7684\u4e3b\u952e\uff0c\u7136\u540e\u8be5\u552f\u4e00\u7d22\u5f15\u5c31\u53ef\u4ee5\u8bbe\u7f6e\u4e3a\u4e0d\u53ef\u89c1\uff0c\u793a\u4f8b\u5982\u4e0b\uff1a<\/p>\n<pre>CREATE TABLE t2 (\n  i INT NOT NULL,\n  j INT NOT NULL,\n  UNIQUE j_idx (j)\n) ENGINE = InnoDB;\nmysql&gt; ALTER TABLE t2 ALTER INDEX j_idx INVISIBLE;\nERROR 3522 (HY000): A primary key index cannot be invisible.\nALTER TABLE t2 ADD PRIMARY KEY (i);\nmysql&gt; ALTER TABLE t2 ALTER INDEX j_idx INVISIBLE;\nQuery OK, 0 rows affected (0.03 sec)<\/pre>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>MySQL 8.0 \u7248\u672c\u652f\u6301\u4e0d\u53ef\u89c1\u7d22\u5f15\uff08Invisible Indexes\uff09\uff0c\u4e5f\u5c31\u662f\u7d22\u5f15\u5bf9\u4f18\u5316\u5668\u4e0d\u53ef\u89c1\uff0c\u65e0\u6cd5\u4f7f &hellip;<\/p>\n<p class=\"read-more\"> <a class=\"\" href=\"http:\/\/www.weijing.co\/?p=5378\"> <span class=\"screen-reader-text\">MySQL \u4e0d\u53ef\u89c1\u7d22\u5f15 (Invisible Indexes)<\/span> \u67e5\u770b\u5168\u6587 &raquo;<\/a><\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":""},"categories":[90,88],"tags":[],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"mailpoet_newsletter_max":false,"woocommerce_thumbnail":false,"woocommerce_single":false,"woocommerce_gallery_thumbnail":false,"shop_catalog":false,"shop_single":false,"shop_thumbnail":false},"uagb_author_info":{"display_name":"weijing","author_link":"http:\/\/www.weijing.co\/?author=4"},"uagb_comment_info":0,"uagb_excerpt":"MySQL 8.0 \u7248\u672c\u652f\u6301\u4e0d\u53ef\u89c1\u7d22\u5f15\uff08Invisible Indexes\uff09\uff0c\u4e5f\u5c31\u662f\u7d22\u5f15\u5bf9\u4f18\u5316\u5668\u4e0d\u53ef\u89c1\uff0c\u65e0\u6cd5\u4f7f&hellip;","_links":{"self":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/5378"}],"collection":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5378"}],"version-history":[{"count":0,"href":"http:\/\/www.weijing.co\/index.php?rest_route=\/wp\/v2\/posts\/5378\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5378"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5378"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.weijing.co\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5378"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}