\u7d22\u5f15\u53ca\u6267\u884c\u8ba1\u5212<\/title><\/p>\n<h1>1. \u7d22\u5f15\u4f5c\u7528<\/h1>\n<p> <\/p>\n<pre><code class=\"language-undefined\" lang=\"undefined\">\u63d0\u4f9b\u4e86\u7c7b\u4f3c\u4e8e\u4e66\u4e2d\u76ee\u5f55\u7684\u4f5c\u7528,\u76ee\u7684\u662f\u4e3a\u4e86\u4f18\u5316\u67e5\u8be2\n<\/code><\/pre>\n<h1>2. \u7d22\u5f15\u7684\u79cd\u7c7b(\u7b97\u6cd5)<\/h1>\n<p> <\/p>\n<pre><code class=\"language-undefined\" lang=\"undefined\">B\u6811\u7d22\u5f15\nHash\u7d22\u5f15\nR\u6811\nFull text\nGIS \n<\/code><\/pre>\n<h1>3. B\u6811 \u57fa\u4e8e\u4e0d\u540c\u7684\u67e5\u627e\u7b97\u6cd5\u5206\u7c7b\u4ecb\u7ecd<\/h1>\n<p><img decoding=\"async\" src=\"https:\/\/\/\/upload-images.jianshu.io\/upload_images\/16956686-0408e2dc5dbd0a54.png?imageMogr2\/auto-orient\/strip|imageView2\/2\/w\/1200\/format\/webp\" referrerpolicy=\"no-referrer\" alt=\"img\"><\/p>\n<p>image.png<\/p>\n<p> <\/p>\n<pre><code class=\"language-jsx\" lang=\"jsx\">B-tree\nB+Tree \u5728\u8303\u56f4\u67e5\u8be2\u65b9\u9762\u63d0\u4f9b\u4e86\u66f4\u597d\u7684\u6027\u80fd(> < >= <= like)\nB*Tree\n<\/code><\/pre>\n<h1>4. \u5728\u529f\u80fd\u4e0a\u7684\u5206\u7c7b<\/h1>\n<h2>4.1 \u8f85\u52a9\u7d22\u5f15(S)\u600e\u4e48\u6784\u5efaB\u6811\u7ed3\u6784\u7684?<\/h2>\n<pre><code class=\"language-csharp\" lang=\"csharp\">(1)\u63d0\u53d6\u7d22\u5f15\u5217\u7684\u6240\u6709\u503c,\u8fdb\u884c\u6392\u5e8f\n(2)\u5c06\u6392\u597d\u5e8f\u7684\u503c,\u5747\u5300\u7684\u5b58\u653e\u5728\u53f6\u5b50\u8282\u70b9,\u8fdb\u4e00\u6b65\u751f\u6210\u679d\u8282\u70b9\u548c\u6839\u8282\u70b9\n(3)\u5728\u53f6\u5b50\u8282\u70b9\u4e2d\u7684\u503c,\u90fd\u4f1a\u5bf9\u5e94\u5b58\u50a8\u4e3b\u952eID\n\nid name age gender\nselect * from t1 where id=10;\n\u95ee\u9898: \u57fa\u4e8e\u7d22\u5f15\u952e\u505awhere\u67e5\u8be2,\u5bf9\u4e8eid\u5217\u662f\u987a\u5e8fIO,\u4f46\u662f\u5bf9\u4e8e\u5176\u4ed6\u5217\u7684\u67e5\u8be2,\u53ef\u80fd\u662f\u968f\u673aIO.\n<\/code><\/pre>\n<h2>4.2 \u805a\u96c6\u7d22\u5f15(C)<\/h2>\n<h3>4.2.1 \u524d\u63d0<\/h3>\n<pre><code class=\"language-undefined\" lang=\"undefined\">(1)MySQL\u4f1a\u81ea\u52a8\u9009\u62e9\u4e3b\u952e\u4f5c\u4e3a\u805a\u96c6\u7d22\u5f15\u5217,\u6ca1\u6709\u4e3b\u952e\u4f1a\u9009\u62e9\u552f\u4e00\u952e,\u5982\u679c\u90fd\u6ca1\u6709\u4f1a\u751f\u6210\u9690\u85cf\u7684.\n(2)MySQL\u8fdb\u884c\u5b58\u50a8\u6570\u636e\u65f6,\u4f1a\u6309\u7167\u805a\u96c6\u7d22\u5f15\u5217\u503c\u5f97\u987a\u5e8f,\u6709\u5e8f\u5b58\u50a8\u6570\u636e\u884c\n(3)\u805a\u96c6\u7d22\u5f15\u76f4\u63a5\u5c06\u539f\u8868\u6570\u636e\u9875,\u4f5c\u4e3a\u53f6\u5b50\u8282\u70b9,\u7136\u540e\u63d0\u53d6\u805a\u96c6\u7d22\u5f15\u5217\u5411.\u4e0a\u751f\u6210\u679d\u548c\u6839\n<\/code><\/pre>\n<h3>4.2.2 \u8f85\u52a9\u7d22\u5f15(S)\u600e\u4e48\u6784\u5efaB\u6811\u7ed3\u6784\u7684?<\/h3>\n<pre><code class=\"language-undefined\" lang=\"undefined\">(1) \u5728\u5efa\u8868\u65f6,\u8bbe\u7f6e\u4e86\u4e3b\u952e\u5217(ID)\n(2) \u5728\u5c06\u6765\u5f55\u5165\u6570\u636e\u65f6,\u5c31\u4f1a\u6309\u7167ID\u5217\u7684\u987a\u5e8f\u5b58\u50a8\u5230\u78c1\u76d8\u4e0a.(\u6211\u4eec\u53c8\u79f0\u4e4b\u4e3a\u805a\u96c6\u7d22\u5f15\u7ec4\u7ec7\u8868)\n(3) \u5c06\u6392\u597d\u5e8f\u7684\u6574\u884c\u6570\u636e,\u751f\u6210\u53f6\u5b50\u8282\u70b9.\u53ef\u4ee5\u7406\u89e3\u4e3a,\u78c1\u76d8\u7684\u6570\u636e\u9875\u5c31\u662f\u53f6\u5b50\u8282\u70b9\n<\/code><\/pre>\n<h3>4.2.3 \u805a\u96c6\u7d22\u5f15\u548c\u8f85\u52a9\u7d22\u5f15\u6784\u6210\u533a\u522b<\/h3>\n<pre><code class=\"language-undefined\" lang=\"undefined\">\u805a\u96c6\u7d22\u5f15\u53ea\u80fd\u6709\u4e00\u4e2a,\u975e\u7a7a\u552f\u4e00,\u4e00\u822c\u662f\u4e3b\u952e\n\u8f85\u52a9\u7d22\u5f15,\u53ef\u4ee5\u6709\u591a\u4e2a,\u662f\u914d\u5408\u805a\u96c6\u7d22\u5f15\u4f7f\u7528\u7684\uff0c\u8868\u4e2d\u4efb\u4f55\u4e00\u4e2a\u5217\u90fd\u53ef\u4ee5\u521b\u5efa\u8f85\u52a9\u7d22\u5f15,\u5728\u4f60\u6709\u9700\u8981\u7684\u65f6\u5019,\u53ea\u8981\u540d\u5b57\u4e0d\u540c\u5373\u53ef\n\n\u805a\u96c6\u7d22\u5f15\u53f6\u5b50\u8282\u70b9,\u5c31\u662f\u78c1\u76d8\u7684\u6570\u636e\u884c\u5b58\u50a8\u7684\u6570\u636e\u9875\n\u8f85\u52a9\u7d22\u5f15,\u53f6\u5b50\u8282\u70b9\u53ea\u5b58\u50a8\u7d22\u5f15\u5217\u7684\u6709\u5e8f\u503c+\u805a\u96c6\u7d22\u5f15\u5217\u503c\nMySQL\u7684\u8868\u6570\u636e\u5b58\u50a8\u662f\u805a\u96c6\u7d22\u5f15\u7ec4\u7ec7\u8868\n<\/code><\/pre>\n<p><img decoding=\"async\" src=\"https:\/\/\/\/upload-images.jianshu.io\/upload_images\/16956686-e9678b5133528566.png?imageMogr2\/auto-orient\/strip|imageView2\/2\/w\/1085\/format\/webp\" referrerpolicy=\"no-referrer\" alt=\"img\"><\/p>\n<p>image.png<\/p>\n<h1>5.\u8f85\u52a9\u7d22\u5f15\u7ec6\u5206<\/h1>\n<p> <\/p>\n<pre><code class=\"language-undefined\" lang=\"undefined\">1.\u666e\u901a\u7684\u5355\u5217\u8f85\u52a9\u7d22\u5f15\n2.\u8054\u5408\u7d22\u5f15\uff08\u8986\u76d6\u7d22\u5f15\uff09\uff0c\u591a\u4e2a\u5217\u4f5c\u4e3a\u7d22\u5f15\u6761\u4ef6,\u751f\u6210\u7d22\u5f15\u6811,\u7406\u8bba\u4e0a\u8bbe\u8ba1\u7684\u597d\u7684,\u53ef\u4ee5\u51cf\u5c11\u5927\u91cf\u7684\u56de\u8868\u67e5\u8be2\n3.\u552f\u4e00\u7d22\u5f15\uff0c\u7d22\u5f15\u5217\u7684\u503c\u90fd\u662f\u552f\u4e00\u7684.\n<\/code><\/pre>\n<h1>6. \u5173\u4e8e\u7d22\u5f15\u6811\u7684\u9ad8\u5ea6<\/h1>\n<p>\u7d22\u5f15\u6811\u9ad8\u5ea6\u5e94\u5f53\u8d8a\u4f4e\u8d8a\u597d,\u4e00\u822c\u7ef4\u6301\u57283-4\u6700\u4f73<\/p>\n<pre><code class=\"language-csharp\" lang=\"csharp\">1. \u6570\u636e\u884c\u6570\u8fc7\u591a, \u89e3\u51b3\u65b9\u6cd5:\n\u5206\u8868\uff0cparttion\u7528\u7684\u6bd4\u8f83\u5c11\u4e86\n\u5206\u5e93,\u5206\u5e03\u5f0f\n \n2. \u7d22\u5f15\u5217\u503c\u8fc7\u957f, \u89e3\u51b3\u65b9\u6cd5:\n\u4e1a\u52a1\u5141\u8bb8,\u5c3d\u91cf\u9009\u62e9\u5b57\u7b26\u957f\u5ea6\u77ed\u7684\u5217\u4f5c\u4e3a\u7d22\u5f15\u5217\n\u4e1a\u52a1\u4e0d\u5141\u8bb8,\u91c7\u7528\u524d\u7f00\u7d22\u5f15\n \n3. \u6570\u636e\u7c7b\u578b:\n\u53d8\u957f\u957f\u5ea6\u5b57\u7b26\u4e32,\u4f7f\u7528\u4e86char,\u89e3\u51b3\u65b9\u6848:\n\u53d8\u957f\u5b57\u7b26\u4e32\u4f7f\u7528varchar\nenum\u7c7b\u578b\u7684\u4f7f\u7528enum \uff08255\u4ee5\u5185\uff0c\u53ea\u53601\u5b57\u8282\uff09\n<\/code><\/pre>\n<h1>7. \u7d22\u5f15\u7684\u57fa\u672c\u7ba1\u7406<\/h1>\n<h2>7.1 \u67e5\u8be2\u7d22\u5f15<\/h2>\n<pre><code class=\"language-mysql\" lang=\"mysql\">mysql> desc user;\n+-----------+--------------+------+-----+---------+----------------+\n| Field | Type | Null | Key | Default | Extra |\n+-----------+--------------+------+-----+---------+----------------+\n| uid | int(11) | NO | PRI | NULL | auto_increment |\n| uname | varchar(255) | YES | | NULL | |\n| upassword | varchar(255) | YES | | NULL | |\n| rid | int(11) | YES | MUL | NULL | |\n| utel | varchar(255) | YES | | NULL | |\n| ustatus | int(255) | YES | | NULL | |\n| uimg | varchar(255) | YES | | NULL | |\n+-----------+--------------+------+-----+---------+----------------+\n7 rows in set (0.00 sec)\n\nmysql> show index from user\\G\n*************************** 1. row ***************************\n Table: user\n Non_unique: 0\n Key_name: PRIMARY\n Seq_in_index: 1\n Column_name: uid\n Collation: A\n Cardinality: 21\n Sub_part: NULL\n Packed: NULL\n Null: \n Index_type: BTREE\n Comment: \nIndex_comment: \n*************************** 2. row ***************************\n Table: user\n Non_unique: 1\n Key_name: user_role\n Seq_in_index: 1\n Column_name: rid\n Collation: A\n Cardinality: 3\n Sub_part: NULL\n Packed: NULL\n Null: YES\n Index_type: BTREE\n Comment: \nIndex_comment: \n2 rows in set (0.00 sec)\n\n\nField :\u5217\u540d\u5b57\nkey :\u6709\u6ca1\u6709\u7d22\u5f15,\u7d22\u5f15\u7c7b\u578b\nPRI: \u4e3b\u952e\u7d22\u5f15\nUNI: \u552f\u4e00\u7d22\u5f15\nMUL: \u8f85\u52a9\u7d22\u5f15(\u5355\u5217,\u8054\u548c,\u524d\u7f00)\n<\/code><\/pre>\n<h2>7.2 \u521b\u5efa\u7d22\u5f15<\/h2>\n<h3>7.2.1\u5355\u5217\u7684\u8f85\u52a9\u7d22\u5f15<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">db01 [world]>alter table city add index idx_name(name);\n \u8868 \u7d22\u5f15\u540d\uff08\u5217\u540d\uff09\ndb01 [world]>create index idx_name1 on city(name);\ndb01 [world]>show index from city;\n\u6ce8\u610f:\n\u4ee5\u4e0a\u64cd\u4f5c\u4e0d\u4ee3\u8868\u751f\u4ea7\u64cd\u4f5c,\u6211\u4eec\u4e0d\u5efa\u8bae\u5728\u4e00\u4e2a\u5217\u4e0a\u5efa\u591a\u4e2a\u7d22\u5f15\n\u540c\u4e00\u4e2a\u8868\u4e2d\uff0c\u7d22\u5f15\u540d\u4e0d\u80fd\u540c\u540d\u3002\n\n<\/code><\/pre>\n<h3>7.2.2 \u8986\u76d6\u7d22\u5f15(\u591a\u5217\u7684\u8054\u5408\u7d22\u5f15)<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">Master [world]>alter table city add index idx_co_po(countrycode,population);\n<\/code><\/pre>\n<h3>7.2.3 \u524d\u7f00\u7d22\u5f15<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">db01 [world]>alter table city add index idx_di(district(5));\n\u6ce8\u610f\uff1a\u6570\u5b57\u5217\u4e0d\u80fd\u7528\u4f5c\u524d\u7f00\u7d22\u5f15\uff0c\u53ea\u80fd\u9488\u5bf9\u5b57\u7b26\u4e32\u3002\n<\/code><\/pre>\n<h3>7.2.4 \u552f\u4e00\u7d22\u5f15<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">db01 [world]>alter table city add unique index idx_uni1(name);\nERROR 1062 (23000): Duplicate entry 'San Jose' for key 'idx_uni1'\n<\/code><\/pre>\n<p>\u7edf\u8ba1city\u8868\u4e2d\uff0c\u4ee5\u7701\u7684\u540d\u5b57\u4e3a\u5206\u7ec4\uff0c\u7edf\u8ba1\u7ec4\u7684\u4e2a\u6570<\/p>\n<pre><code class=\"language-csharp\" lang=\"csharp\">select district,count(id) from city group by district;\n\u9700\u6c42: \u627e\u5230world\u4e0b,city\u8868\u4e2d name\u5217\u6709\u91cd\u590d\u503c\u7684\u884c,\u6700\u540e\u5220\u6389\u91cd\u590d\u7684\u884c\ndb01 [world]>select name,count(id) as cid from city group by name having cid>1 order by cid desc;\ndb01 [world]>select * from city where name='suzhou';\n<\/code><\/pre>\n<h3>7.2.5 \u5220\u9664\u7d22\u5f15:<\/h3>\n<pre><code class=\"language-mysql\" lang=\"mysql\">db01 [world]>alter table city drop index idx_name1;\n \u8868\u540d \u7d22\u5f15\u540d\n<\/code><\/pre>\n<h1>8.\u538b\u529b\u6d4b\u8bd5\u51c6\u5907<\/h1>\n<pre><code class=\"language-mysql\" lang=\"mysql\">mysq1> use test\nmysql> source \/ tmp\/t100w.sql \n<\/code><\/pre>\n<h2>8.1\u672a\u505a\u4f18\u5316\u4e4b\u524d\u6d4b\u8bd5<\/h2>\n<pre><code class=\"language-mysql\" lang=\"mysql\">mysqlslap --defaults-file=\/etc\/my.cnf \\\n--concurrency=100 --iterations=1 --create-schema='test' \\\n--query=\"select * from test.t100w where k2='cuoni'\" engine=innodb \\\n--number-of-queries=2000 -uroot -p1 -verbose\n<\/code><\/pre>\n<p> <\/p>\n<h1>9. \u6267\u884c\u8ba1\u5212\u5206\u6790<\/h1>\n<h2>9.0 \u4f5c\u7528<\/h2>\n<pre><code class=\"language-csharp\" lang=\"csharp\">(1)\n\u83b7\u53d6\u5230\u7684\u662f\u4f18\u5316\u5668\u9009\u62e9\u5b8c\u6210\u7684,\u4ed6\u8ba4\u4e3a\u4ee3\u4ef7\u6700\u5c0f\u7684\u6267\u884c\u8ba1\u5212.\n\u4f5c\u7528: \u8bed\u53e5\u6267\u884c\u524d,\u5148\u770b\u6267\u884c\u8ba1\u5212\u4fe1\u606f,\u53ef\u4ee5\u6709\u6548\u7684\u9632\u6b62\u6027\u80fd\u8f83\u5dee\u7684\u8bed\u53e5\u5e26\u6765\u7684\u6027\u80fd\u95ee\u9898.\n\u5982\u679c\u4e1a\u52a1\u4e2d\u51fa\u73b0\u4e86\u6162\u8bed\u53e5\uff0c\u6211\u4eec\u4e5f\u9700\u8981\u501f\u52a9\u6b64\u547d\u4ee4\u8fdb\u884c\u8bed\u53e5\u7684\u8bc4\u4f30\uff0c\u5206\u6790\u4f18\u5316\u65b9\u6848\u3002\n(2) select \u83b7\u53d6\u6570\u636e\u7684\u65b9\u6cd5\n1. \u5168\u8868\u626b\u63cf(\u5e94\u5f53\u5c3d\u91cf\u907f\u514d,\u56e0\u4e3a\u6027\u80fd\u4f4e)\n2. \u7d22\u5f15\u626b\u63cf\n3. \u83b7\u53d6\u4e0d\u5230\u6570\u636e\n<\/code><\/pre>\n<h2>9.1 \u6267\u884c\u8ba1\u5212\u83b7\u53d6<\/h2>\n<p>\u83b7\u53d6\u4f18\u5316\u5668\u9009\u62e9\u540e\u7684\u6267\u884c\u8ba1\u5212<\/p>\n<pre><code class=\"language-mysql\" lang=\"mysql\">desc SQL\u8bed\u53e5\n\nexplain SQL\u8bed\u53e5\n<\/code><\/pre>\n<p> <\/p>\n<h2>9.2 \u6267\u884c\u8ba1\u5212\u5206\u6790<\/h2>\n<h3>9.2.0 \u91cd\u70b9\u5173\u6ce8\u7684\u4fe1\u606f<\/h3>\n<pre><code class=\"language-shell\" lang=\"shell\">table: city ---->\u67e5\u8be2\u64cd\u4f5c\u7684\u8868 **\npossible_keys: CountryCode,idx_co_po ---->\u53ef\u80fd\u4f1a\u8d70\u7684\u7d22\u5f15 **\nkey: CountryCode \t\t\t\t\t\t ---->\u771f\u6b63\u8d70\u7684\u7d22\u5f15 ***\ntype: ref \t\t\t\t\t\t\t\t ---->\u67e5\u8be2\u7c7b\u578b *****\n\nExtra: Using index condition ---->\u989d\u5916\u4fe1\u606f *****\n<\/code><\/pre>\n<h3>9.2.1 type\u8be6\u89e3<\/h3>\n<pre><code class=\"language-php\" lang=\"php\">\u4ece\u5de6\u5230\u53f3\u6027\u80fd\u4f9d\u6b21\u53d8\u597d.\nALL : \n\u5168\u8868\u626b\u63cf,\u4e0d\u8d70\u7d22\u5f15\n\u4f8b\u5b50:\n1. \u67e5\u8be2\u6761\u4ef6\u5217,\u6ca1\u6709\u7d22\u5f15\nSELECT * FROM t_100w WHERE k2='780P'; \n2. \u67e5\u8be2\u6761\u4ef6\u51fa\u73b0\u4ee5\u4e0b\u8bed\u53e5(\u8f85\u52a9\u7d22\u5f15\u5217)\nUSE world \nDESC city;\nDESC SELECT * FROM city WHERE countrycode <> 'CHN';\nDESC SELECT * FROM city WHERE countrycode NOT IN ('CHN','USA');\nDESC SELECT * FROM city WHERE countrycode LIKE '%CH%';\n\u6ce8\u610f:\u5bf9\u4e8e\u805a\u96c6\u7d22\u5f15\u5217,\u4f7f\u7528\u4ee5\u4e0a\u8bed\u53e5,\u4f9d\u7136\u4f1a\u8d70\u7d22\u5f15\nDESC SELECT * FROM city WHERE id <> 10;\n\nINDEX :\n\u5168\u7d22\u5f15\u626b\u63cf\n1. \u67e5\u8be2\u9700\u8981\u83b7\u53d6\u6574\u4e2a\u7d22\u5f15\u6811\u79cd\u7684\u503c\u65f6:\nDESC SELECT countrycode FROM city;\n\n2. \u8054\u5408\u7d22\u5f15\u4e2d,\u4efb\u4f55\u4e00\u4e2a\u975e\u6700\u5de6\u5217\u4f5c\u4e3a\u67e5\u8be2\u6761\u4ef6\u65f6:\nidx_a_b_c(a,b,c) ---> a ab abc\n\nSELECT * FROM t1 WHERE b \nSELECT * FROM t1 WHERE c \n\nRANGE :\n\u7d22\u5f15\u8303\u56f4\u626b\u63cf \n\u8f85\u52a9\u7d22\u5f15> < >= <= LIKE IN OR \n\u4e3b\u952e <> NOT IN\n\n\u4f8b\u5b50:\n1. \nDESC SELECT * FROM city WHERE id<5;\n2. \nDESC SELECT * FROM city WHERE countrycode LIKE 'CH%';\n3. \nDESC SELECT * FROM city WHERE countrycode IN ('CHN','USA');\n\n\u6ce8\u610f: \n1\u548c2\u4f8b\u5b50\u4e2d,\u53ef\u4ee5\u4eab\u53d7\u5230B+\u6811\u7684\u4f18\u52bf,\u4f46\u662f3\u4f8b\u5b50\u4e2d\u662f\u4e0d\u80fd\u4eab\u53d7\u7684.\n\u6240\u4ee5,\u6211\u4eec\u53ef\u4ee5\u5c063\u53f7\u5217\u5b50\u6539\u5199:\n\nDESC SELECT * FROM city WHERE countrycode='CHN'\nUNION ALL \nSELECT * FROM city WHERE countrycode='USA';\nref: \n\u975e\u552f\u4e00\u6027\u7d22\u5f15,\u7b49\u503c\u67e5\u8be2\nDESC SELECT * FROM city WHERE countrycode='CHN';\n\neq_ref: \n\u5728\u591a\u8868\u8fde\u63a5\u65f6,\u8fde\u63a5\u6761\u4ef6\u4f7f\u7528\u4e86\u552f\u4e00\u7d22\u5f15(uk pK)\n\nDESC SELECT b.name,a.name FROM city AS a \nJOIN country AS b \nON a.countrycode=b.code \nWHERE a.population <100;\nDESC country\nsystem,const :\n\u552f\u4e00\u7d22\u5f15\u7684\u7b49\u503c\u67e5\u8be2\nDESC SELECT * FROM city WHERE id=10;\n<\/code><\/pre>\n<h3>9.2.2 \u5176\u4ed6\u5b57\u6bb5\u89e3\u91ca<\/h3>\n<p> <\/p>\n<pre><code class=\"language-kotlin\" lang=\"kotlin\">extra: \nfilesort ,\u6587\u4ef6\u6392\u5e8f.\nSHOW INDEX FROM city;\nALTER TABLE city ADD INDEX CountryCode(CountryCode);\nALTER TABLE city DROP INDEX idx_c_p;\n\nDESC SELECT * FROM city WHERE countrycode='CHN' ORDER BY population \n\nALTER TABLE city ADD INDEX idx_(population);\nDESC SELECT * FROM city WHERE countrycode='CHN' ORDER BY population \nALTER TABLE city ADD INDEX idx_c_p(countrycode,population);\nALTER TABLE city DROP INDEX idx_;\nALTER TABLE city DROP INDEX CountryCode;\nDESC SELECT * FROM city WHERE countrycode='CHN' ORDER BY population \n\n\u7ed3\u8bba: \n1.\u5f53\u6211\u4eec\u770b\u5230\u6267\u884c\u8ba1\u5212extra\u4f4d\u7f6e\u51fa\u73b0filesort,\u8bf4\u660e\u7531\u6587\u4ef6\u6392\u5e8f\u51fa\u73b0\n2.\u89c2\u5bdf\u9700\u8981\u6392\u5e8f(ORDER BY,GROUP BY ,DISTINCT )\u7684\u6761\u4ef6,\u6709\u6ca1\u6709\u7d22\u5f15\n3. \u6839\u636e\u5b50\u53e5\u7684\u6267\u884c\u987a\u5e8f,\u53bb\u521b\u5efa\u8054\u5408\u7d22\u5f15\n\n\u7d22\u5f15\u4f18\u5316\u6548\u679c\u6d4b\u8bd5:\n\u4f18\u5316\u524d:\n[root@db01 ~]# mysqlslap --defaults-file=\/etc\/my.cnf \\\n> --concurrency=100 --iterations=1 --create-schema='oldboy' \\\n> --query=\"select * from oldboy.t_100w where k2='780P'\" engine=innodb \\\n> --number-of-queries=2000 -uroot -p123 -verbose\nmysqlslap: [Warning] Using a password on the command line interface can be insecure.\nBenchmark\n Running for engine rbose\n Average number of seconds to run all queries: 701.743 seconds\n Minimum number of seconds to run all queries: 701.743 seconds\n Maximum number of seconds to run all queries: 701.743 seconds\n Number of clients running queries: 100\n Average number of queries per client: 20\n\n\u4f18\u5316\u540e:\n[root@db01 ~]# mysqlslap --defaults-file=\/etc\/my.cnf --concurrency=100 --iterations=1 --create-schema='oldboy' --query=\"select * from oldboy.t_100w where k2='780P'\" engine=innodb --number-of-queries=2000 -uroot -p123 -verbose\nmysqlslap: [Warning] Using a password on the command line interface can be insecure.\nBenchmark\n Running for engine rbose\n Average number of seconds to run all queries: 0.190 seconds\n Minimum number of seconds to run all queries: 0.190 seconds\n Maximum number of seconds to run all queries: 0.190 seconds\n Number of clients running queries: 100\n Average number of queries per client: 20\n\n\u8054\u5408\u7d22\u5f15:\n1. SELECT * FROM t1 WHERE a= b= \n\u6211\u4eec\u5efa\u7acb\u8054\u5408\u7d22\u5f15\u65f6:\nALTER TABLE t1 ADD INDEX idx_a_b(a,b); \nALTER TABLE t1 ADD INDEX idx_b_a(b,a); \n\u4ee5\u4e0a\u7684\u67e5\u8be2\u4e0d\u8003\u8651\u7d22\u5f15\u7684\u987a\u5e8f,\u4f18\u5316\u5668\u4f1a\u81ea\u52a8\u8c03\u6574where\u7684\u6761\u4ef6\u987a\u5e8f\n\u6ce8\u610f: \u7d22\u5f15,\u6211\u4eec\u5728\u8fd9\u79cd\u60c5\u51b5\u4e0b\u5efa\u7d22\u5f15\u65f6,\u9700\u8981\u8003\u8651\u54ea\u4e2a\u5217\u7684\u552f\u4e00\u503c\u66f4\u591a,\u54ea\u4e2a\u653e\u5728\u7d22\u5f15\u5de6\u8fb9.\n\n2. \u5982\u679c\u51fa\u73b0where \u6761\u4ef6\u4e2d\u51fa\u73b0\u4e0d\u7b49\u503c\u67e5\u8be2\u6761\u4ef6\nDESC SELECT * FROM t_100w WHERE num <1000 AND k2='DEEF';\n\u6211\u4eec\u5efa\u7d22\u5f15\u65f6:\nALTER TABLE t_100w ADD INDEX idx_2_n(k2,num);\n\u8bed\u53e5\u4e66\u5199\u65f6\nDESC SELECT * FROM t_100w WHERE k2='DEEF' AND num <1000 ;\n3. \u5982\u679c\u67e5\u8be2\u4e2d\u51fa\u73b0\u591a\u5b50\u53e5\n\u6211\u4eec\u8981\u6309\u7167\u5b50\u53e5\u7684\u6267\u884c\u987a\u5e8f\u8fdb\u884c\u5efa\u7acb\u7d22\u5f15.\n<\/code><\/pre>\n<h3>9.2.3 explain(desc)\u4f7f\u7528\u573a\u666f\uff08\u9762\u8bd5\u9898\uff09<\/h3>\n<p> <\/p>\n<pre><code class=\"language-css\" lang=\"css\">\u9898\u76ee\u610f\u601d: \u6211\u4eec\u516c\u53f8\u4e1a\u52a1\u6162,\u8bf7\u4f60\u4ece\u6570\u636e\u5e93\u7684\u89d2\u5ea6\u5206\u6790\u539f\u56e0\n1.mysql\u51fa\u73b0\u6027\u80fd\u95ee\u9898,\u6211\u603b\u7ed3\u6709\u4e24\u79cd\u60c5\u51b5:\n\uff081\uff09\u5e94\u6025\u6027\u7684\u6162\uff1a\u7a81\u7136\u592f\u4f4f\n\u5e94\u6025\u60c5\u51b5:\u6570\u636e\u5e93hang(\u5361\u4e86,\u8d44\u6e90\u8017\u5c3d)\n\u5904\u7406\u8fc7\u7a0b:\n1.show processlist; \u83b7\u53d6\u5230\u5bfc\u81f4\u6570\u636e\u5e93hang\u7684\u8bed\u53e5\n2. explain \u5206\u6790SQL\u7684\u6267\u884c\u8ba1\u5212,\u6709\u6ca1\u6709\u8d70\u7d22\u5f15,\u7d22\u5f15\u7684\u7c7b\u578b\u60c5\u51b5\n3. \u5efa\u7d22\u5f15,\u6539\u8bed\u53e5\n\uff082\uff09\u4e00\u6bb5\u65f6\u95f4\u6162(\u6301\u7eed\u6027\u7684):\n(1)\u8bb0\u5f55\u6162\u65e5\u5fd7slowlog,\u5206\u6790slowlog\n(2)explain \u5206\u6790SQL\u7684\u6267\u884c\u8ba1\u5212,\u6709\u6ca1\u6709\u8d70\u7d22\u5f15,\u7d22\u5f15\u7684\u7c7b\u578b\u60c5\u51b5\n(3)\u5efa\u7d22\u5f15,\u6539\u8bed\u53e5\n<\/code><\/pre>\n<h1>10. \u7d22\u5f15\u5e94\u7528\u89c4\u8303<\/h1>\n<pre><code class=\"language-rust\" lang=\"rust\">\u4e1a\u52a1\n1.\u4ea7\u54c1\u7684\u529f\u80fd\n2.\u7528\u6237\u7684\u884c\u4e3a\n\"\u70ed\"\u67e5\u8be2\u8bed\u53e5 --->\u8f83\u6162--->slowlog\n\"\u70ed\"\u6570\u636e\n<\/code><\/pre>\n<h2>10.1 \u5efa\u7acb\u7d22\u5f15\u7684\u539f\u5219\uff08DBA\u8fd0\u7ef4\u89c4\u8303\uff09<\/h2>\n<h3>10.1.0 \u8bf4\u660e<\/h3>\n<pre><code class=\"language-undefined\" lang=\"undefined\">\u4e3a\u4e86\u4f7f\u7d22\u5f15\u7684\u4f7f\u7528\u6548\u7387\u66f4\u9ad8\uff0c\u5728\u521b\u5efa\u7d22\u5f15\u65f6\uff0c\u5fc5\u987b\u8003\u8651\u5728\u54ea\u4e9b\u5b57\u6bb5\u4e0a\u521b\u5efa\u7d22\u5f15\u548c\u521b\u5efa\u4ec0\u4e48\u7c7b\u578b\u7684\u7d22\u5f15\u3002\u90a3\u4e48\u7d22\u5f15\u8bbe\u8ba1\u539f\u5219\u53c8\u662f\u600e\u6837\u7684?\n<\/code><\/pre>\n<h3>10.1.1 (\u5fc5\u987b\u7684) \u5efa\u8868\u65f6\u4e00\u5b9a\u8981\u6709\u4e3b\u952e,\u4e00\u822c\u662f\u4e2a\u65e0\u5173\u5217\uff0c\u81ea\u589e\u957f<\/h3>\n<h3>10.1.2 \u9009\u62e9\u552f\u4e00\u6027\u7d22\u5f15<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">\u552f\u4e00\u6027\u7d22\u5f15\u7684\u503c\u662f\u552f\u4e00\u7684\uff0c\u53ef\u4ee5\u66f4\u5feb\u901f\u7684\u901a\u8fc7\u8be5\u7d22\u5f15\u6765\u786e\u5b9a\u67d0\u6761\u8bb0\u5f55\u3002\n\u4f8b\u5982\uff0c\u5b66\u751f\u8868\u4e2d\u5b66\u53f7\u662f\u5177\u6709\u552f\u4e00\u6027\u7684\u5b57\u6bb5\u3002\u4e3a\u8be5\u5b57\u6bb5\u5efa\u7acb\u552f\u4e00\u6027\u7d22\u5f15\u53ef\u4ee5\u5f88\u5feb\u7684\u786e\u5b9a\u67d0\u4e2a\u5b66\u751f\u7684\u4fe1\u606f\u3002\n\u5982\u679c\u4f7f\u7528\u59d3\u540d\u7684\u8bdd\uff0c\u53ef\u80fd\u5b58\u5728\u540c\u540d\u73b0\u8c61\uff0c\u4ece\u800c\u964d\u4f4e\u67e5\u8be2\u901f\u5ea6\u3002\n\n\u4f18\u5316\u65b9\u6848:\n(1) \u5982\u679c\u975e\u5f97\u4f7f\u7528\u91cd\u590d\u503c\u8f83\u591a\u7684\u5217\u4f5c\u4e3a\u67e5\u8be2\u6761\u4ef6(\u4f8b\u5982:\u7537\u5973),\u53ef\u4ee5\u5c06\u8868\u903b\u8f91\u62c6\u5206\n(2) \u53ef\u4ee5\u5c06\u6b64\u5217\u548c\u5176\u4ed6\u7684\u67e5\u8be2\u7c7b,\u505a\u8054\u548c\u7d22\u5f15\nselect count(*) from world.city;\nselect count(distinct countrycode) from world.city;\nselect count(distinct countrycode,population ) from world.city;\n<\/code><\/pre>\n<h3>10.1.3(\u5fc5\u987b\u7684) \u4e3a\u7ecf\u5e38\u9700\u8981where \u3001ORDER BY\u3001GROUP BY,join on\u7b49\u64cd\u4f5c\u7684\u5b57\u6bb5\uff0c<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">\u6392\u5e8f\u64cd\u4f5c\u4f1a\u6d6a\u8d39\u5f88\u591a\u65f6\u95f4\u3002\nwhere A B C ----\u300b A B C\nin \nwhere A group by B order by C\nA,B\uff0cC\n\n\u5982\u679c\u4e3a\u5176\u5efa\u7acb\u7d22\u5f15\uff0c\u4f18\u5316\u67e5\u8be2\n\u6ce8\uff1a\u5982\u679c\u7ecf\u5e38\u4f5c\u4e3a\u6761\u4ef6\u7684\u5217\uff0c\u91cd\u590d\u503c\u7279\u522b\u591a\uff0c\u53ef\u4ee5\u5efa\u7acb\u8054\u5408\u7d22\u5f15\u3002\n<\/code><\/pre>\n<h3>10.1.4 \u5c3d\u91cf\u4f7f\u7528\u524d\u7f00\u6765\u7d22\u5f15<\/h3>\n<pre><code class=\"language-undefined\" lang=\"undefined\">\u5982\u679c\u7d22\u5f15\u5b57\u6bb5\u7684\u503c\u5f88\u957f\uff0c\u6700\u597d\u4f7f\u7528\u503c\u7684\u524d\u7f00\u6765\u7d22\u5f15\u3002\n<\/code><\/pre>\n<h3>10.1.5 \u9650\u5236\u7d22\u5f15\u7684\u6570\u76ee<\/h3>\n<pre><code class=\"language-undefined\" lang=\"undefined\">\u7d22\u5f15\u7684\u6570\u76ee\u4e0d\u662f\u8d8a\u591a\u8d8a\u597d\u3002\n\u53ef\u80fd\u4f1a\u4ea7\u751f\u7684\u95ee\u9898:\n(1) \u6bcf\u4e2a\u7d22\u5f15\u90fd\u9700\u8981\u5360\u7528\u78c1\u76d8\u7a7a\u95f4\uff0c\u7d22\u5f15\u8d8a\u591a\uff0c\u9700\u8981\u7684\u78c1\u76d8\u7a7a\u95f4\u5c31\u8d8a\u5927\u3002\n(2) \u4fee\u6539\u8868\u65f6\uff0c\u5bf9\u7d22\u5f15\u7684\u91cd\u6784\u548c\u66f4\u65b0\u5f88\u9ebb\u70e6\u3002\u8d8a\u591a\u7684\u7d22\u5f15\uff0c\u4f1a\u4f7f\u66f4\u65b0\u8868\u53d8\u5f97\u5f88\u6d6a\u8d39\u65f6\u95f4\u3002\n(3) \u4f18\u5316\u5668\u7684\u8d1f\u62c5\u4f1a\u5f88\u91cd,\u6709\u53ef\u80fd\u4f1a\u5f71\u54cd\u5230\u4f18\u5316\u5668\u7684\u9009\u62e9.\npercona-toolkit\u4e2d\u6709\u4e2a\u5de5\u5177,\u4e13\u95e8\u5206\u6790\u7d22\u5f15\u662f\u5426\u6709\u7528\n<\/code><\/pre>\n<h3>10.1.6 \u5220\u9664\u4e0d\u518d\u4f7f\u7528\u6216\u8005\u5f88\u5c11\u4f7f\u7528\u7684\u7d22\u5f15(percona toolkit)<\/h3>\n<pre><code class=\"language-undefined\" lang=\"undefined\">pt-duplicate-key-checker\n\n\u8868\u4e2d\u7684\u6570\u636e\u88ab\u5927\u91cf\u66f4\u65b0\uff0c\u6216\u8005\u6570\u636e\u7684\u4f7f\u7528\u65b9\u5f0f\u88ab\u6539\u53d8\u540e\uff0c\u539f\u6709\u7684\u4e00\u4e9b\u7d22\u5f15\u53ef\u80fd\u4e0d\u518d\u9700\u8981\u3002\u6570\u636e\u5e93\u7ba1\u7406\n\u5458\u5e94\u5f53\u5b9a\u671f\u627e\u51fa\u8fd9\u4e9b\u7d22\u5f15\uff0c\u5c06\u5b83\u4eec\u5220\u9664\uff0c\u4ece\u800c\u51cf\u5c11\u7d22\u5f15\u5bf9\u66f4\u65b0\u64cd\u4f5c\u7684\u5f71\u54cd\u3002\n<\/code><\/pre>\n<h3>10.1.7 \u5927\u8868\u52a0\u7d22\u5f15,\u8981\u5728\u4e1a\u52a1\u4e0d\u7e41\u5fd9\u671f\u95f4\u64cd\u4f5c<\/h3>\n<h3>10.1.8 \u5c3d\u91cf\u5c11\u5728\u7ecf\u5e38\u66f4\u65b0\u503c\u7684\u5217\u4e0a\u5efa\u7d22\u5f15<\/h3>\n<h3>10.1.9 \u5efa\u7d22\u5f15\u539f\u5219<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">(1) \u5fc5\u987b\u8981\u6709\u4e3b\u952e,\u5982\u679c\u6ca1\u6709\u53ef\u4ee5\u505a\u4e3a\u4e3b\u952e\u6761\u4ef6\u7684\u5217,\u521b\u5efa\u65e0\u5173\u5217\n(2) \u7ecf\u5e38\u505a\u4e3awhere\u6761\u4ef6\u5217 order by group by join on, distinct \u7684\u6761\u4ef6(\u4e1a\u52a1:\u4ea7\u54c1\u529f\u80fd+\u7528\u6237\u884c\u4e3a)\n(3) \u6700\u597d\u4f7f\u7528\u552f\u4e00\u503c\u591a\u7684\u5217\u4f5c\u4e3a\u7d22\u5f15,\u5982\u679c\u7d22\u5f15\u5217\u91cd\u590d\u503c\u8f83\u591a,\u53ef\u4ee5\u8003\u8651\u4f7f\u7528\u8054\u5408\u7d22\u5f15\n(4) \u5217\u503c\u957f\u5ea6\u8f83\u957f\u7684\u7d22\u5f15\u5217,\u6211\u4eec\u5efa\u8bae\u4f7f\u7528\u524d\u7f00\u7d22\u5f15.\n(5) \u964d\u4f4e\u7d22\u5f15\u6761\u76ee,\u4e00\u65b9\u9762\u4e0d\u8981\u521b\u5efa\u6ca1\u7528\u7d22\u5f15,\u4e0d\u5e38\u4f7f\u7528\u7684\u7d22\u5f15\u6e05\u7406,percona toolkit(xxxxx)\n(6) \u7d22\u5f15\u7ef4\u62a4\u8981\u907f\u5f00\u4e1a\u52a1\u7e41\u5fd9\u671f\n(7) \u5c0f\u8868\u4e0d\u5efa\u7acb\u7d22\u5f15\n<\/code><\/pre>\n<h2>10.2 \u4e0d\u8d70\u7d22\u5f15\u7684\u60c5\u51b5\uff08\u5f00\u53d1\u89c4\u8303\uff09<\/h2>\n<h3>10.2.1 \u6ca1\u6709\u67e5\u8be2\u6761\u4ef6\uff0c\u6216\u8005\u67e5\u8be2\u6761\u4ef6\u6ca1\u6709\u5efa\u7acb\u7d22\u5f15<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">select * from tab; \u5168\u8868\u626b\u63cf\u3002\nselect * from tab where 1=1;\n\u5728\u4e1a\u52a1\u6570\u636e\u5e93\u4e2d\uff0c\u7279\u522b\u662f\u6570\u636e\u91cf\u6bd4\u8f83\u5927\u7684\u8868\u3002\n\u662f\u6ca1\u6709\u5168\u8868\u626b\u63cf\u8fd9\u79cd\u9700\u6c42\u3002\n1\u3001\u5bf9\u7528\u6237\u67e5\u770b\u662f\u975e\u5e38\u75db\u82e6\u7684\u3002\n2\u3001\u5bf9\u670d\u52a1\u5668\u6765\u8bb2\u6bc1\u706d\u6027\u7684\u3002\n\uff081\uff09\nselect * from tab;\nSQL\u6539\u5199\u6210\u4ee5\u4e0b\u8bed\u53e5\uff1a\nselect * from tab order by price limit 10 ; \u9700\u8981\u5728price\u5217\u4e0a\u5efa\u7acb\u7d22\u5f15\n\uff082\uff09\nselect * from tab where name='zhangsan' name\u5217\u6ca1\u6709\u7d22\u5f15\n\u6539\uff1a\n1\u3001\u6362\u6210\u6709\u7d22\u5f15\u7684\u5217\u4f5c\u4e3a\u67e5\u8be2\u6761\u4ef6\n2\u3001\u5c06name\u5217\u5efa\u7acb\u7d22\u5f15\n<\/code><\/pre>\n<h3>10.2.2 \u67e5\u8be2\u7ed3\u679c\u96c6\u662f\u539f\u8868\u4e2d\u7684\u5927\u90e8\u5206\u6570\u636e\uff0c\u5e94\u8be5\u662f25\uff05\u4ee5\u4e0a\u3002<\/h3>\n<pre><code class=\"language-objectivec\" lang=\"objectivec\">\u67e5\u8be2\u7684\u7ed3\u679c\u96c6\uff0c\u8d85\u8fc7\u4e86\u603b\u6570\u884c\u657025%\uff0c\u4f18\u5316\u5668\u89c9\u5f97\u5c31\u6ca1\u6709\u5fc5\u8981\u8d70\u7d22\u5f15\u4e86\u3002\n\n\u5047\u5982\uff1atab\u8868 id\uff0cname id:1-100w \uff0cid\u5217\u6709(\u8f85\u52a9)\u7d22\u5f15\nselect * from tab where id>500000;\n\u5982\u679c\u4e1a\u52a1\u5141\u8bb8\uff0c\u53ef\u4ee5\u4f7f\u7528limit\u63a7\u5236\u3002\n\u600e\u4e48\u6539\u5199 \uff1f\n\u7ed3\u5408\u4e1a\u52a1\u5224\u65ad\uff0c\u6709\u6ca1\u6709\u66f4\u597d\u7684\u65b9\u5f0f\u3002\u5982\u679c\u6ca1\u6709\u66f4\u597d\u7684\u6539\u5199\u65b9\u6848\n\u5c3d\u91cf\u4e0d\u8981\u5728mysql\u5b58\u653e\u8fd9\u4e2a\u6570\u636e\u4e86\u3002\u653e\u5230redis\u91cc\u9762\u3002\n<\/code><\/pre>\n<h3>10.2.3 \u7d22\u5f15\u672c\u8eab\u5931\u6548\uff0c\u7edf\u8ba1\u6570\u636e\u4e0d\u771f\u5b9e<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">\u7d22\u5f15\u6709\u81ea\u6211\u7ef4\u62a4\u7684\u80fd\u529b\u3002\n\u5bf9\u4e8e\u8868\u5185\u5bb9\u53d8\u5316\u6bd4\u8f83\u9891\u7e41\u7684\u60c5\u51b5\u4e0b\uff0c\u6709\u53ef\u80fd\u4f1a\u51fa\u73b0\u7d22\u5f15\u5931\u6548\u3002\n\u4e00\u822c\u662f\u5220\u9664\u91cd\u5efa\n \n\u9762\u8bd5\u9898:\u540c\u4e00\u4e2a\u8bed\u53e5\u7a81\u7136\u53d8\u6162?\n\u7edf\u8ba1\u4fe1\u606f\u8fc7\u65e7\uff0c\u5bfc\u81f4\u7684\u7d22\u5f15\u5931\u6548\n\n\u73b0\u8c61:\n\u6709\u4e00\u6761select\u8bed\u53e5\u5e73\u5e38\u67e5\u8be2\u65f6\u5f88\u5feb,\u7a81\u7136\u6709\u4e00\u5929\u5f88\u6162,\u4f1a\u662f\u4ec0\u4e48\u539f\u56e0\nselect? --->\u7d22\u5f15\u5931\u6548,\uff0c\u7edf\u8ba1\u6570\u636e\u4e0d\u771f\u5b9e\nDML ? --->\u9501\u51b2\u7a81\n<\/code><\/pre>\n<h3>10.2.4 \u67e5\u8be2\u6761\u4ef6\u4f7f\u7528\u51fd\u6570\u5728\u7d22\u5f15\u5217\u4e0a\uff0c\u6216\u8005\u5bf9\u7d22\u5f15\u5217\u8fdb\u884c\u8fd0\u7b97\uff0c\u8fd0\u7b97\u5305\u62ec(+\uff0c-\uff0c*\uff0c\/\uff0c! \u7b49)<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">\u4f8b\u5b50\uff1a\n\u9519\u8bef\u7684\u4f8b\u5b50\uff1aselect * from test where id-1=9;\n\u6b63\u786e\u7684\u4f8b\u5b50\uff1aselect * from test where id=10;\n\u7b97\u672f\u8fd0\u7b97\n\u51fd\u6570\u8fd0\u7b97\n\u5b50\u67e5\u8be2\n<\/code><\/pre>\n<h3>10.2.5 \u9690\u5f0f\u8f6c\u6362\u5bfc\u81f4\u7d22\u5f15\u5931\u6548.\u8fd9\u4e00\u70b9\u5e94\u5f53\u5f15\u8d77\u91cd\u89c6.\u4e5f\u662f\u5f00\u53d1\u4e2d\u7ecf\u5e38\u4f1a\u72af\u7684\u9519\u8bef.<\/h3>\n<pre><code class=\"language-ruby\" lang=\"ruby\">\u8fd9\u6837\u4f1a\u5bfc\u81f4\u7d22\u5f15\u5931\u6548. \u9519\u8bef\u7684\u4f8b\u5b50\uff1a\nmysql> alter table tab add index inx_tel(telnum);\nQuery OK, 0 rows affected (0.03 sec)\nRecords: 0 Duplicates: 0 Warnings: 0\nmysql>\nmysql> desc tab;\n+--------+-------------+------+-----+---------+-------+\n| Field | Type | Null | Key | Default | Extra |\n+--------+-------------+------+-----+---------+-------+\n| id | int(11) | YES | | NULL | |\n| name | varchar(20) | YES | | NULL | |\n| telnum | varchar(20) | YES | MUL | NULL | |\n+--------+-------------+------+-----+---------+-------+\n3 rows in set (0.01 sec)\nmysql> select * from tab where telnum='1333333';\n+------+------+---------+\n| id | name | telnum |\n+------+------+---------+\n| 1 | a | 1333333 |\n+------+------+---------+\n1 row in set (0.00 sec)\nmysql> select * from tab where telnum=1333333;\n+------+------+---------+\n| id | name | telnum |\n+------+------+---------+\n| 1 | a | 1333333 |\n+------+------+---------+\n1 row in set (0.00 sec)\nmysql> explain select * from tab where telnum='1333333';\n+----+-------------+-------+------+---------------+---------+---------+-------+------+-----------------------+\n| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |\n+----+-------------+-------+------+---------------+---------+---------+-------+------+-----------------------+\n\n| 1 | SIMPLE | tab | ref | inx_tel | inx_tel | 63 | const | 1 | Using index condition |\n+----+-------------+-------+------+---------------+---------+---------+-------+------+-----------------------+\n1 row in set (0.00 sec)\nmysql> explain select * from tab where telnum=1333333;\n+----+-------------+-------+------+---------------+------+---------+------+------+-------------+\n| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |\n+----+-------------+-------+------+---------------+------+---------+------+------+-------------+\n| 1 | SIMPLE | tab | ALL | inx_tel | NULL | NULL | NULL | 2 | Using where |\n+----+-------------+-------+------+---------------+------+---------+------+------+-------------+\n1 row in set (0.00 sec)\nmysql> explain select * from tab where telnum=1555555;\n+----+-------------+-------+------+---------------+------+---------+------+------+-------------+\n| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |\n+----+-------------+-------+------+---------------+------+---------+------+------+-------------+\n| 1 | SIMPLE | tab | ALL | inx_tel | NULL | NULL | NULL | 2 | Using where |\n+----+-------------+-------+------+---------------+------+---------+------+------+-------------+\n1 row in set (0.00 sec)\nmysql> explain select * from tab where telnum='1555555';\n+----+-------------+-------+------+---------------+---------+---------+-------+------+-----------------------+\n| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |\n+----+-------------+-------+------+---------------+---------+---------+-------+------+-----------------------+\n| 1 | SIMPLE | tab | ref | inx_tel | inx_tel | 63 | const | 1 | Using index condition |\n+----+-------------+-------+------+---------------+---------+---------+-------+------+-----------------------+\n1 row in set (0.00 sec)\nmysql>\n<\/code><\/pre>\n<h3>10.2.6 <> \uff0cnot in \u4e0d\u8d70\u7d22\u5f15\uff08\u8f85\u52a9\u7d22\u5f15\uff09<\/h3>\n<pre><code class=\"language-csharp\" lang=\"csharp\">EXPLAIN SELECT * FROM teltab WHERE telnum <> '110';\nEXPLAIN SELECT * FROM teltab WHERE telnum NOT IN ('110','119');\n\nmysql> select * from tab where telnum <> '1555555';\n+------+------+---------+\n| id | name | telnum |\n+------+------+---------+\n| 1 | a | 1333333 |\n+------+------+---------+\n1 row in set (0.00 sec)\nmysql> explain select * from tab where telnum <> '1555555';\n\n\u5355\u72ec\u7684>,<,in \u6709\u53ef\u80fd\u8d70\uff0c\u4e5f\u6709\u53ef\u80fd\u4e0d\u8d70\uff0c\u548c\u7ed3\u679c\u96c6\u6709\u5173\uff0c\u5c3d\u91cf\u7ed3\u5408\u4e1a\u52a1\u6dfb\u52a0limit\nor\u6216in \u5c3d\u91cf\u6539\u6210union\nEXPLAIN SELECT * FROM teltab WHERE telnum IN ('110','119');\n\u6539\u5199\u6210\uff1a\nEXPLAIN SELECT * FROM teltab WHERE telnum='110'\nUNION ALL\nSELECT * FROM teltab WHERE telnum='119'\n<\/code><\/pre>\n<h3>10.2.7 like “%_” \u767e\u5206\u53f7\u5728\u6700\u524d\u9762\u4e0d\u8d70<\/h3>\n<pre><code class=\"language-go\" lang=\"go\">EXPLAIN SELECT * FROM teltab WHERE telnum LIKE '31%' \u8d70range\u7d22\u5f15\u626b\u63cf\nEXPLAIN SELECT * FROM teltab WHERE telnum LIKE '%110' \u4e0d\u8d70\u7d22\u5f15\n%linux%\u7c7b\u7684\u641c\u7d22\u9700\u6c42\uff0c\u53ef\u4ee5\u4f7f\u7528elasticsearch+mongodb \u4e13\u95e8\u505a\u641c\u7d22\u670d\u52a1\u7684\u6570\u636e\u5e93\u4ea7\u54c1\n<\/code><\/pre>\n<h3>10.2.8 \u8054\u5408\u7d22\u5f15\u8868<\/h3>\n<pre><code>\u8054\u5408\u7d22\u5f15: t1 (id,k1 , k2 ,k3) idx (k1 ;k2 ;k3)\n1.\u5728where\u6761\u4ef6\u4e2d\u90fd\u662f\u7b49\u503c\u7684where k1=xx k2= =xx k3=xxx \u65e0\u5173where\u6761\u4ef6\u7684\u987a\u5e8f,\u53ea\u8981\u628a\u63a7\u5efa\u7d22\u5f15\u65f6\uff0c\u9700\u8981\u628a\u552f\u4e00-\u503c\u8f83\u591a\u7684\u653e\u5728\u6700\u5de6\u4fa7.\n2.\u5728\u6761\u4ef6\u67e5\u8be2\u4e2d\u6ca1\u6709\u6700\u5de6\u5217\u6761\u4ef6\u65f6;\u6ca1\u6709K1\u5217\u7684\u67e5\u8be2,\u90fd\u662f\u4e0d\u8d70\u7d22\u5f15\u7684 \u610f\u5916\u60c5\u51b5:\u5c06\u8868\u4e2d\u6240\u6709\u5217\u5efa\u7acb\u8054\u5408,\u6ca1\u6709\u4e2a\u5217\u505a\u67e5\u8be2\u6761\u4ef6\u90fd\u4f1a\u8d70\u7d22\u5f15(\u4e86\u89e3)\n3.\u5982\u679c\u67e5\u8be2\u4e2d\u51fa\u73b0(> < >=<= like) \na= and b<xxx and C=XXX\n\u5efa\u7d22\u5f15\u65f6\u5c06\u7b49\u503c\u67e5\u8be2\u6761\u4ef6\u5f80\u524d\u653e;\u4e0d\u7b49\u503c\u7684\u653e\u5728\u6700\u540e\n4.\u591a\u5b50\u53e5\u65f6\uff0c\u4e25\u683c\u6309\u987a\u5e8f\u6267\u884c\uff0c\u6839\u636e\u8bed\u53e5\uff0c\u5efa\u7acb\u7d22\u5f15\n<\/code><\/pre>\n<p> 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[…]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6],"tags":[],"class_list":["post-61","post","type-post","status-publish","format-standard","hentry","category-mysql"],"_links":{"self":[{"href":"https:\/\/daishen.ltd\/index.php?rest_route=\/wp\/v2\/posts\/61","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/daishen.ltd\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/daishen.ltd\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/daishen.ltd\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/daishen.ltd\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=61"}],"version-history":[{"count":1,"href":"https:\/\/daishen.ltd\/index.php?rest_route=\/wp\/v2\/posts\/61\/revisions"}],"predecessor-version":[{"id":62,"href":"https:\/\/daishen.ltd\/index.php?rest_route=\/wp\/v2\/posts\/61\/revisions\/62"}],"wp:attachment":[{"href":"https:\/\/daishen.ltd\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=61"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/daishen.ltd\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=61"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/daishen.ltd\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=61"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}