{"id":41731,"date":"2022-12-19T02:32:48","date_gmt":"2023-09-18T02:36:58","guid":{"rendered":"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/"},"modified":"2024-04-29T05:56:17","modified_gmt":"2024-04-28T21:56:17","slug":"mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/","title":{"rendered":"MySQL\u548cPostgreSQL\u7684Explain\u7684\u4f7f\u7528\u65b9\u6cd5"},"content":{"rendered":"<h1>\u9996\u5148<\/h1>\n<p>\u6211\u662fHRBrain\u682a\u5f0f\u4f1a\u793e\u7684\u5de5\u7a0b\u5e08\u3002\u6211\u5df2\u7ecf\u505a\u5de5\u7a0b\u5e08\u5de5\u4f5c\u8fd16\u5e74\u4e86\u3002\u5728\u8fd9\u671f\u95f4\uff0c\u6211\u67095\u5e74\u4ee5\u4e0a\u7684MySQL\u5de5\u4f5c\u7ecf\u9a8c\u3002\u76ee\u524d\uff0c\u6211\u6240\u5728\u7684HRBrain\u516c\u53f8\u4e3b\u8981\u4f7f\u7528PostgreSQL\u4f5c\u4e3a\u4e3b\u8981\u6570\u636e\u5e93\u3002\u5728\u4f7f\u7528PostgreSQL\u671f\u95f4\uff0c\u5f53\u6267\u884cExplain\u529f\u80fd\u65f6\uff0c\u6211\u53d1\u73b0\u5176\u4e0eMySQL\u663e\u793a\u5185\u5bb9\u5b8c\u5168\u4e0d\u540c\u3002\u56e0\u6b64\uff0c\u6211\u5c06\u5206\u522b\u89e3\u91caMySQL\u548cPostgreSQL\u7684Explain\u6240\u663e\u793a\u7684\u6267\u884c\u8ba1\u5212\u3002<\/p>\n<h1>\u89e3\u91ca\u662f\u6307\u901a\u8fc7\u63cf\u8ff0\u6216\u8bf4\u660e\uff0c\u4f7f\u67d0\u4e8b\u6216\u67d0\u4e2a\u6982\u5ff5\u53d8\u5f97\u66f4\u6e05\u6670\u6216\u66f4\u5bb9\u6613\u7406\u89e3\u7684\u884c\u4e3a\u3002<\/h1>\n<p>\u663e\u793aSQL\u67e5\u8be2\u6267\u884c\u8ba1\u5212\u7684\u529f\u80fd\u3002<br \/>\n\u53ef\u4ee5\u67e5\u770b\u67e5\u8be2\u89c4\u5212\u5668\u6267\u884c\u67e5\u8be2\u7684\u65b9\u5f0f\uff0c<br \/>\n\u53ef\u7528\u4e8e\u4f18\u5316\u67e5\u8be2\u6027\u80fd\u7b49\u64cd\u4f5c\u3002<\/p>\n<p>\u53ea\u9700\u5728\u6267\u884c\u67e5\u8be2\u7684\u5f00\u5934\u52a0\u4e0aExplain\u5373\u53ef\u6267\u884c\u3002<\/p>\n<h1>\u63d0\u524d\u51c6\u5907<\/h1>\n<h2>\u5173\u4e8e\u5982\u4f55\u89e3\u91ca\uff08Explain\uff09\u67e5\u8be2\u3002<\/h2>\n<p>\u6211\u5728PostgreSQL\u548cMySQL\u4e2d\u5206\u522b\u521b\u5efa\u4e86\u4ee5\u4e0b\u8868\u683c\u3002<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">users: \u30e6\u30fc\u30b6\u60c5\u5831<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">department: \u90e8\u7f72\u60c5\u5831<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">orders: \u6ce8\u6587\u60c5\u5831<\/ul>\n<h2>\u5b9e\u4f53\u5173\u7cfb\u56fe<\/h2>\n<div><img decoding=\"async\" class=\"post-images\" title=\"\" src=\"https:\/\/cdn.silicloud.com\/blog-img\/blog\/img\/657d483b37434c4406caae2b\/10-0.png\" alt=\"ER.png\" \/><\/div>\n<p>\u6211\u4eec\u5c06\u4f7f\u7528\u4ee5\u4e0b\u67e5\u8be2\u6765\u67e5\u770bMySQL\u548cPostgreSQL\u7684Explain\u8be6\u7ec6\u4fe1\u606f\u3002<\/p>\n<pre class=\"post-pre\"><code><span class=\"k\">EXPLAIN<\/span> \r\n<span class=\"kr\">SELECT<\/span> \r\n  <span class=\"k\">users<\/span><span class=\"p\">.<\/span><span class=\"n\">name<\/span><span class=\"p\">,<\/span> \r\n  <span class=\"n\">department<\/span><span class=\"p\">.<\/span><span class=\"n\">name<\/span> <span class=\"kr\">AS<\/span> <span class=\"n\">department_name<\/span><span class=\"p\">,<\/span> \r\n  <span class=\"nf\">COUNT<\/span><span class=\"p\">(<\/span><span class=\"n\">orders<\/span><span class=\"p\">.<\/span><span class=\"n\">id<\/span><span class=\"p\">)<\/span> <span class=\"kr\">AS<\/span> <span class=\"n\">order_count<\/span> \r\n<span class=\"kr\">FROM<\/span> \r\n  <span class=\"k\">users<\/span> \r\n  <span class=\"k\">JOIN<\/span> <span class=\"n\">department<\/span> <span class=\"kr\">ON<\/span> <span class=\"k\">users<\/span><span class=\"p\">.<\/span><span class=\"n\">department_id<\/span> <span class=\"o\">=<\/span> <span class=\"n\">department<\/span><span class=\"p\">.<\/span><span class=\"n\">id<\/span> \r\n  <span class=\"k\">LEFT<\/span> <span class=\"k\">JOIN<\/span> <span class=\"n\">orders<\/span> <span class=\"kr\">ON<\/span> <span class=\"k\">users<\/span><span class=\"p\">.<\/span><span class=\"n\">id<\/span> <span class=\"o\">=<\/span> <span class=\"n\">orders<\/span><span class=\"p\">.<\/span><span class=\"n\">user_id<\/span> \r\n<span class=\"kr\">WHERE<\/span> \r\n  <span class=\"k\">users<\/span><span class=\"p\">.<\/span><span class=\"n\">age<\/span> <span class=\"o\">&gt;<\/span> <span class=\"mi\">25<\/span> \r\n<span class=\"kr\">GROUP<\/span> <span class=\"kr\">BY<\/span> \r\n  <span class=\"k\">users<\/span><span class=\"p\">.<\/span><span class=\"n\">id<\/span><span class=\"p\">,<\/span> \r\n  <span class=\"n\">department<\/span><span class=\"p\">.<\/span><span class=\"n\">id<\/span><span class=\"p\">;<\/span>\r\n<\/code><\/pre>\n<h1>\u5982\u4f55\u67e5\u770b\u6267\u884c\u8ba1\u5212<\/h1>\n<h2>MySQL\u67e5\u8be2\u7684\u7ed3\u679c<\/h2>\n<div><img decoding=\"async\" class=\"post-images\" title=\"\" src=\"https:\/\/cdn.silicloud.com\/blog-img\/blog\/img\/657d483b37434c4406caae2b\/15-0.png\" alt=\"\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8 2023-07-16 17.32.19.png\" \/><\/div>\n<p>MySQL\u7684Explain\u529f\u80fd\u5c06\u6267\u884c\u8ba1\u5212\u4ee5\u8868\u683c\u5f62\u5f0f\u663e\u793a\u51fa\u6765\u3002<\/p>\n<h2>\u9879\u76ee\u8bf4\u660e<\/h2>\n<div><img decoding=\"async\" class=\"post-images\" title=\"\" src=\"https:\/\/cdn.silicloud.com\/blog-img\/blog\/img\/657d483b37434c4406caae2b\/18-0.png\" alt=\"\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8 2023-07-20 16.30.07.png\" \/><\/div>\n<h2>\u89e3\u91c8\u57fa\u65bc\u7d50\u679c\u7684\u67e5\u8a62\u57f7\u884c\u8a08\u5283\u8996\u89d2\u3002<\/h2>\n<ol>\n<li style=\"list-style-type: none;\">\n<ol>users\u8868<\/ol>\n<\/li>\n<\/ol>\n<p>\u7531\u4e8e\u7c7b\u578b\u4e3aALL\uff0cusers\u8868\u5c06\u8fdb\u884c\u5168\u8868\u626b\u63cf\uff08\u8bfb\u53d6\u6240\u6709\u884c\uff09<br \/>\npossible_keys\u663e\u793a\u6709\u4e00\u4e2a\u540d\u4e3adepartment_id\u7684\u7d22\u5f15\uff0c\u4f46\u662fkey\u4e2d\u6ca1\u6709\u663e\u793a\u4efb\u4f55\u4e1c\u897f\uff0c\u6240\u4ee5\u7d22\u5f15\u6ca1\u6709\u88ab\u4f7f\u7528<br \/>\nrows\u4e3a10\uff0c\u8868\u793ausers\u8868\u4e2d\u603b\u5171\u670910\u884c\u6570\u636e<br \/>\n\u7b5b\u9009\u6761\u4ef6\u88ab\u5e94\u7528\u5230\u7684\u884c\u7684\u6bd4\u4f8b\u4e3a33.3%<\/p>\n<p>department\u8868<\/p>\n<p>\u7531\u4e8e\u7c7b\u578b\u4e3aeq_ref\uff0c\u4f7f\u7528\u4e86\u7d22\u5f15\u8fdb\u884c\u7b49\u503c\u8fde\u63a5\uff08*1\uff09<br \/>\nsample.users.department_id\u548cdepartment.id\u4f5c\u4e3a\u8fde\u63a5\u6761\u4ef6<br \/>\nrows\u4e3a1\u8bf4\u660e\uff0c\u5f53\u8fde\u63a5sample.users.id\u548corders.user_id\u65f6\uff0c\u7ed3\u679c\u751f\u6210\u4e861\u884c<br \/>\n\u7b5b\u9009\u6761\u4ef6\u88ab\u5e94\u7528\u5230\u7684\u884c\u7684\u6bd4\u4f8b\u4e3a100%<\/p>\n<p>orders\u8868<\/p>\n<p>\u7531\u4e8e\u7c7b\u578b\u4e3aref\uff0c\u4f7f\u7528\u4e86\u7d22\u5f15\u8fdb\u884c\u8303\u56f4\u8fde\u63a5<br \/>\nsample.users.id\u548corders.user_id\u4f5c\u4e3a\u8fde\u63a5\u6761\u4ef6<br \/>\n\u5f53\u8fde\u63a5sample.users.id\u548corders.user_id\u65f6\uff0corders\u751f\u6210\u4e86\u4e00\u884c<br \/>\n\u67e5\u8be2\u6267\u884c\u5904\u7406\u4e865\u884c<br \/>\n\u7b5b\u9009\u6761\u4ef6\u88ab\u5e94\u7528\u5230\u7684\u884c\u7684\u6bd4\u4f8b\u4e3a100%<\/p>\n<p>\u9700\u8981\u4ece\u8868\u683c\u4e2d\u8bfb\u53d6\u6267\u884c\u987a\u5e8f\u3002<\/p>\n<h2>PostgreSQL\u7684\u7ed3\u679c<\/h2>\n<div><img decoding=\"async\" class=\"post-images\" title=\"\" src=\"https:\/\/cdn.silicloud.com\/blog-img\/blog\/img\/657d483b37434c4406caae2b\/23-0.png\" alt=\"\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8 2023-07-17 0.57.15.png\" \/><\/div>\n<p>PostgreSQL\u7684\u89e3\u91ca\u4e0eMySQL\u7684Explain\u663e\u793a\u5b8c\u5168\u4e0d\u540c\u3002<br \/>\nPostgreSQL\u7684\u89e3\u91ca\u4ee5\u6811\u72b6\u5f62\u5f0f\u663e\u793a\u6267\u884c\u8ba1\u5212\uff0c\u5e76\u4e14\u6bcf\u4e2a\u8282\u70b9\u90fd\u4e0e\u7236\u8282\u70b9\u548c\u5b50\u8282\u70b9\u76f8\u5173\u8054\u3002<\/p>\n<p>\u6211\u5011\u5c07\u67e5\u770b\u986f\u793a\u7684\u5167\u5bb9\u9805\u76ee\u3002<\/p>\n<h2>\u9879\u76ee\u8bf4\u660e<\/h2>\n<div><img decoding=\"async\" class=\"post-images\" title=\"\" src=\"https:\/\/cdn.silicloud.com\/blog-img\/blog\/img\/657d483b37434c4406caae2b\/27-0.png\" alt=\"\u30b9\u30af\u30ea\u30fc\u30f3\u30b7\u30e7\u30c3\u30c8 2023-07-20 16.34.21.png\" \/><\/div>\n<h2>\u89e3\u91cb\u57fa\u65bc\u7d50\u679c\u7684\u67e5\u8a62\u57f7\u884c\u8a08\u5283\u7684\u89c0\u9ede\u3002<\/h2>\n<p>\u9605\u8bfbPostgreSQL\u6267\u884c\u8ba1\u5212\u7684\u89c4\u5219\u6709\u4ee5\u4e0b\u4e24\u4e2a\u3002<\/p>\n<ol>\n<li style=\"list-style-type: none;\">\n<ol>\u6309\u987a\u5e8f\u904d\u5386\u5b50\u8282\u70b9\uff0c\u4ece\u6700\u9065\u8fdc\u7684\u5b50\u5b59\u8282\u70b9\u5f00\u59cb\u6267\u884c\uff0c\u7136\u540e\u5411\u4e0a\u8ffd\u6eaf\u81f3\u7236\u8282\u70b9\u3002<\/ol>\n<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<ol>\u5982\u679c\u5b58\u5728\u5144\u5f1f\u5143\u7d20(\u203b2)\uff0c\u5219\u6309\u7167\u5148\u524d\u7684\u884c\u8fdb\u884c\u4f9d\u6b21\u904d\u5386\u8282\u70b9\u3002<\/ol>\n<p>\u4e3a\u4e86\u66f4\u5bb9\u6613\u7406\u89e3\uff0c\u6211\u4eec\u5c06\u6267\u884c\u8ba1\u5212\u7ed8\u5236\u6210\u56fe\u8868\u3002<\/p>\n<div><img decoding=\"async\" class=\"post-images\" title=\"\" src=\"https:\/\/cdn.silicloud.com\/blog-img\/blog\/img\/657d483b37434c4406caae2b\/32-0.png\" alt=\"postgreSQL_2.png\" \/><\/div>\n<ol>\n<li style=\"list-style-type: none;\">\n<ol>\u626b\u63cforders\u8868\u7684\u6570\u636e<\/ol>\n<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<ol>\n<li style=\"list-style-type: none;\">\n<ol>\u626b\u63cfusers\u8868\u7684\u6570\u636e<\/ol>\n<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<ol>\n<li style=\"list-style-type: none;\">\n<ol>\u521b\u5efa\u7528\u4e8e\u4e0eorders\u8868\u8fdb\u884c\u8fde\u63a5\u7684\u6563\u5217\u8868<\/ol>\n<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<ol>\n<li style=\"list-style-type: none;\">\n<ol>\u626b\u63cfdepartment\u8868<\/ol>\n<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<ol>\n<li style=\"list-style-type: none;\">\n<ol>\u5c06orders\u8868\u548cusers\u8868\u8fdb\u884c\u6563\u5217\u8fde\u63a5<\/ol>\n<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<ol>\n<li style=\"list-style-type: none;\">\n<ol>\u521b\u5efa\u7528\u4e8e\u5c06department\u8868\u548cusers\u8868\u8fde\u63a5\u7684\u6563\u5217\u8868<\/ol>\n<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<ol>\n<li style=\"list-style-type: none;\">\n<ol>\u5c06department\u8868\u548cusers\u8868\u8fdb\u884c\u6563\u5217\u8fde\u63a5<\/ol>\n<\/li>\n<\/ol>\n<p>&nbsp;<\/p>\n<ol>\u6309user.id\u548cdepartment.id\u8fdb\u884c\u5206\u7ec4<\/ol>\n<p>\u8fd9\u91cc\u660e\u786e\u663e\u793a\u4e86\u6267\u884c\u987a\u5e8f\u548c\u67e5\u8be2\u6210\u672c\u7b49\u3002<\/p>\n<h2>\u603b\u7ed3<\/h2>\n<p>MySQL \u662f\u4e00\u79cd\u5f00\u6e90\u7684\u5173\u7cfb\u578b\u6570\u636e\u5e93\u7ba1\u7406\u7cfb\u7edf\u3002<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">MySQL\u306eExplain\u306e\u8868\u793a\u306f12\u306e\u9805\u76ee\u3067\u5b9f\u884c\u8a08\u753b\u304c\u8868\u793a\u3055\u308c\u308b\u3002<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\u8868\u793a\u3055\u308c\u305f12\u9805\u76ee\u306e\u5185\u5bb9\u3092\u8aad\u307f\u53d6\u308a\u5b9f\u884c\u9806\u5e8f\u3092\u8aad\u307f\u53d6\u308b\u5fc5\u8981\u304c\u3042\u308b\u3002<\/ul>\n<p>PostgreSQL\u53ef\u4ee5\u88ab\u7b80\u5355\u5730\u7406\u89e3\u4e3a\u4e00\u79cd\u6570\u636e\u5e93\u7ba1\u7406\u7cfb\u7edf\u3002<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">QUERY PLAN\u3068\u3044\u3046\u30c6\u30ad\u30b9\u30c8\u5f62\u5f0f\u3067\u51fa\u529b\u3055\u308c\u308b\u3002<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">\u9805\u76ee\u306f\u5b9f\u884c\u3057\u305f\u30af\u30a8\u30ea\u306b\u3088\u308a\u5185\u5bb9\u304c\u5909\u308f\u308b\u3002<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">\u5b9f\u884c\u8a08\u753b\u306e\u4e88\u6e2ccost\u7b49\u3092\u51fa\u3057\u3066\u304f\u308c\u308b\u3002<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">\u5b9f\u884c\u9806\u5e8f\u306f\u30c4\u30ea\u30fc\u5f62\u5f0f\u3067\u660e\u793a\u7684\u306b\u8868\u793a\u3055\u308c\u3001\u89aa\u30ce\u30fc\u30c9\u3068\u5b50\u30ce\u30fc\u30c9\u306e\u95a2\u4fc2\u304c\u660e\u78ba\u306b\u793a\u3055\u308c\u308b\u3002<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\u30af\u30a8\u30ea\u306e\u30b3\u30b9\u30c8\u3084\u7d50\u5408\u9806\u5e8f\u306a\u3069\u306e\u8a73\u7d30\u60c5\u5831\u304c\u63d0\u4f9b\u3055\u308c\u308b\u3002<\/ul>\n<p>\u901a\u8fc7\u4f7f\u7528 Explain \u529f\u80fd\u6765\u67e5\u770b\u6267\u884c\u8ba1\u5212\u7684\u5185\u5bb9\uff0c\u91cd\u65b0\u8003\u8651\u7d22\u5f15\u7684\u4f7f\u7528\u65b9\u6cd5\u548c\u67e5\u8be2\u6761\u4ef6\uff0c\u4ee5\u786e\u8ba4\u662f\u5426\u53ef\u4ee5\u521b\u5efa\u66f4\u9ad8\u6027\u80fd\u7684\u67e5\u8be2\u3002<\/p>\n<p>\u4e2a\u4eba\u89c2\u70b9<\/p>\n<p>PostgreSQL Explain\u7684\u663e\u793a\u65b9\u5f0f\u4e0eMySQL\u5b8c\u5168\u4e0d\u540c\uff0c\u4f46\u4e00\u65e6\u7406\u89e3\u4e86\u542b\u4e49\uff0c\u67e5\u8be2\u7684\u6267\u884c\u8ba1\u5212\u5c31\u4f1a\u660e\u786e\u5730\u663e\u793a\u51fa\u6765\uff0c\u8ba9\u4eba\u975e\u5e38\u5bb9\u6613\u7406\u89e3\u3002<\/p>\n<h2>\u586b\u8865<\/h2>\n<p>\u203b1\uff1a\u7b49\u503c\u641c\u7d22\u6307\u7684\u662f\u5728\u8fde\u63a5\u6761\u4ef6\u4e2d\uff0c\u4e24\u4e2a\u8868\u7684\u5217\u4e4b\u95f4\u901a\u8fc7\u76f8\u7b49\u7684\u503c\u8fdb\u884c\u8fde\u63a5\u3002<\/p>\n<p>\u203b2\uff1a\u5144\u5f1f\u5143\u7d20\u6307\u7684\u662f\u5728\u89e3\u91ca\u4e2d\u5177\u6709\u76f8\u540c\u7236\u8282\u70b9\u5e76\u5728\u540c\u4e00\u5c42\u7ea7\u663e\u793a\u7684\u8282\u70b9\u3002\u5728\u793a\u4f8b\u4e2d\uff0cHash Right Join\u662f\u7236\u8282\u70b9\uff0cSeq Scan on orders\u548cHash\u662f\u5144\u5f1f\u5173\u7cfb\u3002<\/p>\n<p>\u53ef\u4ee5\u53c2\u8003\uff1a<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">MySQL 8.0 \u30ea\u30d5\u30a1\u30ec\u30f3\u30b9\u30de\u30cb\u30e5\u30a2\u30eb<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">USE THE INDEX, LUKE!<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\n<li style=\"list-style-type: none;\">\n<ul class=\"post-ul\">\u3010PostgreSQL\u3011Explain\u306e\u898b\u65b9\uff08analyze , cost , scan , sort\uff09\u306b\u3064\u3044\u3066\u306e\u307e\u3068\u3081<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<ul class=\"post-ul\">\u3010PostgreSQL\u3011\u521d\u5fc3\u8005\u3067\u3082\u8aad\u3081\u308b\u5b9f\u884c\u8a08\u753b\u306e\u57fa\u790e\u77e5\u8b58<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u9996\u5148 \u6211\u662fHRBrain\u682a\u5f0f\u4f1a\u793e\u7684\u5de5\u7a0b\u5e08\u3002\u6211\u5df2\u7ecf\u505a\u5de5\u7a0b\u5e08\u5de5\u4f5c\u8fd16\u5e74\u4e86\u3002\u5728\u8fd9\u671f\u95f4\uff0c\u6211\u67095\u5e74\u4ee5\u4e0a\u7684MySQL\u5de5\u4f5c\u7ecf [&hellip;]<\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-41731","post","type-post","status-publish","format-standard","hentry","category-uncategorized"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v21.5 (Yoast SEO v21.5) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>MySQL\u548cPostgreSQL\u7684Explain\u7684\u4f7f\u7528\u65b9\u6cd5 - Blog - Silicon Cloud<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.silicloud.com\/zh\/blog\/mysql\u548cpostgresql\u7684explain\u7684\u4f7f\u7528\u65b9\u6cd5\/\" \/>\n<meta property=\"og:locale\" content=\"zh_CN\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"MySQL\u548cPostgreSQL\u7684Explain\u7684\u4f7f\u7528\u65b9\u6cd5\" \/>\n<meta property=\"og:description\" content=\"\u9996\u5148 \u6211\u662fHRBrain\u682a\u5f0f\u4f1a\u793e\u7684\u5de5\u7a0b\u5e08\u3002\u6211\u5df2\u7ecf\u505a\u5de5\u7a0b\u5e08\u5de5\u4f5c\u8fd16\u5e74\u4e86\u3002\u5728\u8fd9\u671f\u95f4\uff0c\u6211\u67095\u5e74\u4ee5\u4e0a\u7684MySQL\u5de5\u4f5c\u7ecf [&hellip;]\" \/>\n<meta property=\"og:url\" content=\"https:\/\/www.silicloud.com\/zh\/blog\/mysql\u548cpostgresql\u7684explain\u7684\u4f7f\u7528\u65b9\u6cd5\/\" \/>\n<meta property=\"og:site_name\" content=\"Blog - Silicon Cloud\" \/>\n<meta property=\"article:published_time\" content=\"2023-09-18T02:36:58+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2024-04-28T21:56:17+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/cdn.silicloud.com\/blog-img\/blog\/img\/657d483b37434c4406caae2b\/10-0.png\" \/>\n<meta name=\"author\" content=\"\u6e05, \u626c\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u4f5c\u8005\" \/>\n\t<meta name=\"twitter:data1\" content=\"\u6e05, \u626c\" \/>\n\t<meta name=\"twitter:label2\" content=\"\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 \u5206\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\/\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/\",\"url\":\"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/\",\"name\":\"MySQL\u548cPostgreSQL\u7684Explain\u7684\u4f7f\u7528\u65b9\u6cd5 - Blog - Silicon Cloud\",\"isPartOf\":{\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#website\"},\"datePublished\":\"2023-09-18T02:36:58+00:00\",\"dateModified\":\"2024-04-28T21:56:17+00:00\",\"author\":{\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/cb5556d2501da73d864cac945e8d9461\"},\"breadcrumb\":{\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/#breadcrumb\"},\"inLanguage\":\"zh-Hans\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"\u9996\u9875\",\"item\":\"https:\/\/www.silicloud.com\/zh\/blog\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"MySQL\u548cPostgreSQL\u7684Explain\u7684\u4f7f\u7528\u65b9\u6cd5\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#website\",\"url\":\"https:\/\/www.silicloud.com\/zh\/blog\/\",\"name\":\"Blog - Silicon Cloud\",\"description\":\"\",\"inLanguage\":\"zh-Hans\"},{\"@type\":\"Person\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/cb5556d2501da73d864cac945e8d9461\",\"name\":\"\u6e05, \u626c\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"zh-Hans\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/image\/\",\"url\":\"https:\/\/secure.gravatar.com\/avatar\/32a4239de8ff29adace466261d309424a1e5fe9f7e3036bf89fe03f2e3dbe717?s=96&d=mm&r=g\",\"contentUrl\":\"https:\/\/secure.gravatar.com\/avatar\/32a4239de8ff29adace466261d309424a1e5fe9f7e3036bf89fe03f2e3dbe717?s=96&d=mm&r=g\",\"caption\":\"\u6e05, \u626c\"},\"url\":\"https:\/\/www.silicloud.com\/zh\/blog\/author\/qingyang\/\"},{\"@type\":\"ImageObject\",\"inLanguage\":\"zh-Hans\",\"@id\":\"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/#local-main-organization-logo\",\"url\":\"\",\"contentUrl\":\"\",\"caption\":\"Blog - Silicon Cloud\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"MySQL\u548cPostgreSQL\u7684Explain\u7684\u4f7f\u7528\u65b9\u6cd5 - Blog - Silicon Cloud","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/www.silicloud.com\/zh\/blog\/mysql\u548cpostgresql\u7684explain\u7684\u4f7f\u7528\u65b9\u6cd5\/","og_locale":"zh_CN","og_type":"article","og_title":"MySQL\u548cPostgreSQL\u7684Explain\u7684\u4f7f\u7528\u65b9\u6cd5","og_description":"\u9996\u5148 \u6211\u662fHRBrain\u682a\u5f0f\u4f1a\u793e\u7684\u5de5\u7a0b\u5e08\u3002\u6211\u5df2\u7ecf\u505a\u5de5\u7a0b\u5e08\u5de5\u4f5c\u8fd16\u5e74\u4e86\u3002\u5728\u8fd9\u671f\u95f4\uff0c\u6211\u67095\u5e74\u4ee5\u4e0a\u7684MySQL\u5de5\u4f5c\u7ecf [&hellip;]","og_url":"https:\/\/www.silicloud.com\/zh\/blog\/mysql\u548cpostgresql\u7684explain\u7684\u4f7f\u7528\u65b9\u6cd5\/","og_site_name":"Blog - Silicon Cloud","article_published_time":"2023-09-18T02:36:58+00:00","article_modified_time":"2024-04-28T21:56:17+00:00","og_image":[{"url":"https:\/\/cdn.silicloud.com\/blog-img\/blog\/img\/657d483b37434c4406caae2b\/10-0.png"}],"author":"\u6e05, \u626c","twitter_card":"summary_large_image","twitter_misc":{"\u4f5c\u8005":"\u6e05, \u626c","\u9884\u8ba1\u9605\u8bfb\u65f6\u95f4":"1 \u5206"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/","url":"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/","name":"MySQL\u548cPostgreSQL\u7684Explain\u7684\u4f7f\u7528\u65b9\u6cd5 - Blog - Silicon Cloud","isPartOf":{"@id":"https:\/\/www.silicloud.com\/zh\/blog\/#website"},"datePublished":"2023-09-18T02:36:58+00:00","dateModified":"2024-04-28T21:56:17+00:00","author":{"@id":"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/cb5556d2501da73d864cac945e8d9461"},"breadcrumb":{"@id":"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/#breadcrumb"},"inLanguage":"zh-Hans","potentialAction":[{"@type":"ReadAction","target":["https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"\u9996\u9875","item":"https:\/\/www.silicloud.com\/zh\/blog\/"},{"@type":"ListItem","position":2,"name":"MySQL\u548cPostgreSQL\u7684Explain\u7684\u4f7f\u7528\u65b9\u6cd5"}]},{"@type":"WebSite","@id":"https:\/\/www.silicloud.com\/zh\/blog\/#website","url":"https:\/\/www.silicloud.com\/zh\/blog\/","name":"Blog - Silicon Cloud","description":"","inLanguage":"zh-Hans"},{"@type":"Person","@id":"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/cb5556d2501da73d864cac945e8d9461","name":"\u6e05, \u626c","image":{"@type":"ImageObject","inLanguage":"zh-Hans","@id":"https:\/\/www.silicloud.com\/zh\/blog\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/32a4239de8ff29adace466261d309424a1e5fe9f7e3036bf89fe03f2e3dbe717?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/32a4239de8ff29adace466261d309424a1e5fe9f7e3036bf89fe03f2e3dbe717?s=96&d=mm&r=g","caption":"\u6e05, \u626c"},"url":"https:\/\/www.silicloud.com\/zh\/blog\/author\/qingyang\/"},{"@type":"ImageObject","inLanguage":"zh-Hans","@id":"https:\/\/www.silicloud.com\/zh\/blog\/mysql%e5%92%8cpostgresql%e7%9a%84explain%e7%9a%84%e4%bd%bf%e7%94%a8%e6%96%b9%e6%b3%95\/#local-main-organization-logo","url":"","contentUrl":"","caption":"Blog - Silicon Cloud"}]}},"_links":{"self":[{"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/posts\/41731","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/users\/9"}],"replies":[{"embeddable":true,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/comments?post=41731"}],"version-history":[{"count":2,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/posts\/41731\/revisions"}],"predecessor-version":[{"id":83456,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/posts\/41731\/revisions\/83456"}],"wp:attachment":[{"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/media?parent=41731"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/categories?post=41731"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.silicloud.com\/zh\/blog\/wp-json\/wp\/v2\/tags?post=41731"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}