{"id":5118,"date":"2025-04-23T09:34:11","date_gmt":"2025-04-23T01:34:11","guid":{"rendered":"https:\/\/qaqaq.top\/?p=5118"},"modified":"2025-05-03T14:40:46","modified_gmt":"2025-05-03T06:40:46","slug":"oracle-hint","status":"publish","type":"post","link":"https:\/\/qaqaq.top\/?p=5118","title":{"rendered":"Oracle\u2014\u2014Hint"},"content":{"rendered":"\n<h2 class=\"wp-block-heading\">1. Hint\uff08\u63d0\u793a\uff09\u7b80\u4ecb<\/h2>\n\n\n\n<p>Hint\u662fOracle\u4e3a\u4e86\u4e0d\u7834\u574f\u548c\u5176\u4ed6\u6570\u636e\u5e93\u5f15\u64ce\u4e4b\u95f4\u5bf9SQL\u8bed\u53e5\u7684\u517c\u5bb9\u6027\u800c\u63d0\u4f9b\u7684\u4e00\u79cd\u6269\u5c55\u529f\u80fd\uff0c\u5728\u4f18\u5316\u5668\u6267\u884c\u8ba1\u5212\u524d\uff0c\u7528\u6765\u544a\u8bc9\u4f18\u5316\u5668\u6309\u7167\u6211\u4eec\u7684\u544a\u8bc9\u5b83\u7684\u65b9\u5f0f\u751f\u6210\u6267\u884c\u8ba1\u5212\u3002<\/p>\n\n\n\n<p>Oracle\u51b3\u5b9a\u628aHint\u4f5c\u4e3a\u4e00\u79cd\u7279\u6b8a\u7684\u6ce8\u91ca\u6765\u6dfb\u52a0\uff0c\u5b83\u7684\u7279\u6b8a\u6027\u8868\u73b0\u5728\u63d0\u793a\u5fc5\u987b\u7d27\u8ddf\u7740DELETE\u3001INSERT\u3001UPDATE\u6216MERGE\u5173\u952e\u5b57\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">2. Hint\u529f\u80fd<\/h2>\n\n\n\n<p>Hint\u63d0\u4f9b\u7684\u529f\u80fd\u975e\u5e38\u4e30\u5bcc\uff0c\u53ef\u4ee5\u5f88\u7075\u6d3b\u5730\u8c03\u6574\u8bed\u53e5\u7684\u6267\u884c\u8fc7\u7a0b\u3002\u901a\u8fc7Hint\uff0c\u6211\u4eec\u53ef\u4ee5\u8c03\u6574\uff1a<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u4f18\u5316\u5668\u7c7b\u578b<\/li>\n\n\n\n<li>\u4f18\u5316\u5668\u4f18\u5316\u76ee\u6807<\/li>\n\n\n\n<li>\u6570\u636e\u8bfb\u53d6\u65b9\u5f0f(\u8bbf\u95ee\u8def\u5f84)<\/li>\n\n\n\n<li>\u67e5\u8be2\u8f6c\u6362\u7c7b\u578b<\/li>\n\n\n\n<li>\u8868\u95f4\u5173\u8054\u7684\u987a\u5e8f<\/li>\n\n\n\n<li>\u8868\u95f4\u5173\u8054\u7684\u7c7b\u578b<\/li>\n\n\n\n<li>\u5e76\u884c\u7279\u6027<\/li>\n\n\n\n<li>\u5176\u4ed6\u7279\u6027<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\">3. Hint\u7528\u6cd5<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">3.1 \u8bed\u6cd5<\/h3>\n\n\n\n<p>1\uff09\u5173\u952e\u5b57\u8bf4\u660e<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>DELETE\u3001INSERT\u3001SELECT\u548cUPDATE\u662f\u6807\u8bc6\u4e00\u4e2a\u8bed\u53e5\u5757\u5f00\u59cb\u7684\u5173\u952e\u5b57\uff0c\u5305\u542b\u63d0\u793a\u7684\u6ce8\u91ca\u53ea\u80fd\u51fa\u73b0\u5728\u8fd9\u4e9b\u5173\u952e\u5b57\u7684\u540e\u9762\uff0c\u5426\u5219\u63d0\u793a\u65e0\u6548\u3002<\/li>\n\n\n\n<li>&#8220;+&#8221;\u53f7\u8868\u793a\u8be5\u6ce8\u91ca\u662f\u4e00\u4e2a\u63d0\u793a\uff0c\u8be5\u52a0\u53f7\u5fc5\u987b\u7acb\u5373\u8ddf\u5728&#8221;\/*&#8221;\u7684\u540e\u9762\uff0c\u4e2d\u95f4\u4e0d\u80fd\u6709\u7a7a\u683c\u3002<\/li>\n\n\n\n<li>hint\u662f\u4e0b\u9762\u4ecb\u7ecd\u7684\u5177\u4f53\u63d0\u793a\u4e4b\u4e00\uff0c\u5982\u679c\u5305\u542b\u591a\u4e2a\u63d0\u793a\uff0c\u5219\u6bcf\u4e2a\u63d0\u793a\u4e4b\u95f4\u9700\u8981\u7528\u4e00\u4e2a\u6216\u591a\u4e2a\u7a7a\u683c\u9694\u5f00\u3002<\/li>\n\n\n\n<li>text\u662f\u5176\u5b83\u8bf4\u660ehint\u7684\u6ce8\u91ca\u6027\u6587\u672c<\/li>\n<\/ul>\n\n\n\n<p>2\uff09\u63d0\u793a\u4e2d\u7684\u9519\u8bef<\/p>\n\n\n\n<p>\u63d0\u793a\u4e2d\u7684\u8bed\u6cd5\u9519\u8bef\u4e0d\u4f1a\u62a5\u9519\uff0c\u5982\u679c\u89e3\u6790\u5668\u4e0d\u80fd\u89e3\u6790\u5b83\uff0c\u5c31\u4f1a\u628a\u5b83\u770b\u505a\u4e00\u4e2a\u666e\u901a\u6ce8\u91ca\u5904\u7406\u3002\u8fd9\u4e5f\u662f\u5bb9\u6613\u9020\u6210\u56f0\u60d1\u7684\u4e00\u70b9\uff0c\u4f7f\u7528\u7684Hint\u5230\u5e95\u662f\u5426\u8d77\u6548\uff1f\u53ef\u4ee5\u91c7\u7528\u4e00\u4e9b\u624b\u6bb5\uff0c\u68c0\u67e5\u63d0\u793a\u7684\u6709\u6548\u6027\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u90a3\u4e9b\u8bed\u6cd5\u6b63\u786e\u4f46\u5f15\u7528\u5bf9\u8c61\u9519\u8bef\u7684\u63d0\u793a\u662f\u4e0d\u4f1a\u88ab\u62a5\u544a\u7684\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>explain plan + dbms_xplan<\/li>\n<\/ul>\n\n\n\n<p>\u4f7f\u7528dbms_xplan\u8f93\u51fa\u4e2d\u7684note\u9009\u9879\u3002<\/p>\n\n\n\n<p>3\uff09\u63d0\u793a\u4e2d\u7684\u5bf9\u8c61<\/p>\n\n\n\n<p>SELECT \/*+ INDEX(table_name index_name) *\/ &#8230;<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>table_name\u662f\u5fc5\u987b\u8981\u5199\u7684\uff0c\u4e14\u5982\u679c\u5728\u67e5\u8be2\u4e2d\u4f7f\u7528\u4e86\u8868\u7684\u522b\u540d\uff0c\u5728hint\u4e5f\u8981\u7528\u8868\u7684\u522b\u540d\u6765\u4ee3\u66ff\u8868\u540d\u3002<\/li>\n\n\n\n<li>index_name\u53ef\u4ee5\u4e0d\u5fc5\u5199\uff0cOracle\u4f1a\u6839\u636e\u7edf\u8ba1\u503c\u9009\u4e00\u4e2a\u7d22\u5f15\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u7d22\u5f15\u540d\u6216\u8868\u540d\u5199\u9519\u4e86\uff0c\u90a3\u8fd9\u4e2ahint\u5c31\u4f1a\u88ab\u5ffd\u7565\u3002<\/li>\n\n\n\n<li>\u5982\u679c\u6307\u5b9a\u5bf9\u8c61\u662f\u89c6\u56fe\uff0c\u9700\u8981\u6309\u6b64\u65b9\u6cd5\u6307\u5b9a\u3002\/*+hint view.table &#8230;*\/\uff0c\u5176\u4e2dtable\u662fview\u4e2d\u7684\u8868\u3002<\/li>\n\n\n\n<li>\u4e00\u4e2a\u5f88\u5e38\u89c1\u7684\u9519\u8bef\u65f6\uff0c\u5728\u4f7f\u7528\u63d0\u793a\u7684\u65f6\u5019\u6700\u6613\u72af\u7684\u9519\u8bef\u662f\u4e0e\u8868\u7684\u522b\u540d\u6709\u5173\u3002\u6b63\u786e\u7684\u89c4\u5219\u662f\uff0c\u5f53\u5728\u63d0\u793a\u4e2d\u4f7f\u7528\u8868\u65f6\uff0c\u53ea\u8981\u8868\u6709\u522b\u540d\u5c31\u5e94\u8be5\u4f7f\u7528\u522b\u540d\u800c\u4e0d\u662f\u8868\u540d\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3.2 \u63d0\u793a\u7684\u4f5c\u7528\u57df<\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>\u521d\u59cb\u5316\u53c2\u6570\u63d0\u793a\u5bf9\u6574\u4e2aSQL\u8bed\u53e5\u8d77\u4f5c\u7528\uff0c\u5176\u4ed6\u7684\u63d0\u793a\u4ec5\u4ec5\u5bf9\u67e5\u8be2\u5757\u8d77\u4f5c\u7528\u3002\u4ec5\u4ec5\u5bf9\u5355\u4e2a\u67e5\u8be2\u5757\u8d77\u4f5c\u7528\u7684\u63d0\u793a\uff0c\u5fc5\u987b\u5728\u5b83\u63a7\u5236\u7684\u67e5\u8be2\u5757\u5185\u6307\u5b9a\u3002<\/li>\n\n\n\n<li>\u53ef\u4ee5\u4f7f\u7528\u70b9\u53f7\u5f15\u7528\u5305\u542b\u5728\u5176\u4ed6\u67e5\u8be2\u5757(\u5047\u8bbe\u8fd9\u4e9b\u5757\u5df2\u547d\u540d)\u4e2d\u7684\u5bf9\u8c61\u3002\u5168\u5c40\u63d0\u793a\u7684\u8bed\u6cd5\u53ef\u4ee5\u652f\u6301\u4e24\u5c42\u4ee5\u4e0a\u7684\u5f15\u7528\uff0c\u5bf9\u8c61\u95f4\u5fc5\u987b\u7528\u70b9\u53f7\u5206\u9694\u3002<\/li>\n\n\n\n<li>\u67e5\u8be2\u4f18\u5316\u5668\u53ef\u4ee5\u7ed9\u6bcf\u4e2a\u67e5\u8be2\u751f\u6210\u4e00\u4e2a\u67e5\u8be2\u5757\u540d\uff0c\u800c\u4e14\u8fd8\u53ef\u4ee5\u4f7f\u7528\u63d0\u793aqb_name\u624b\u5de5\u4e3a\u6bcf\u4e2a\u67e5\u8be2\u5757\u547d\u540d\u3002\u5927\u591a\u6570\u63d0\u793a\u90fd\u53ef\u4ee5\u901a\u8fc7\u53c2\u6570\u6765\u6307\u5b9a\u5728\u90a3\u4e2a\u67e5\u8be2\u5757\u4e2d\u6709\u6548\u3002<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\">3.3 \u63d0\u793a\u6570\u636e\u5b57\u5178<\/h3>\n\n\n\n<p>Oracle\u572811g\u7684\u7248\u672c\u4e2d\u63d0\u4f9b\u4e86\u4e00\u4e2a\u6570\u636e\u5b57\u5178\u2014V$SQL_HINT\u3002<\/p>\n\n\n\n<p>\u901a\u8fc7\u8fd9\u4e2a\u6570\u636e\u5b57\u5178\u53ef\u4ee5\u770b\u5230\u63d0\u793a\u7684\u51fa\u73b0\u7248\u672c\u3001\u6982\u8981\u6570\u636e\u7248\u672c\u3001SQL\u7279\u6027\u4ee5\u53ca\u76f8\u53cd\u63d0\u793a\u7b49\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">4. Hint\u5206\u7c7b\uff08\u548c\u4f18\u5316\u5668\u76f8\u5173\u7684\uff09<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>OPT_PARAM<\/strong><\/li>\n<\/ul>\n\n\n\n<p>\u5728\u67d0\u6761\u8bed\u53e5\u4e2d\u6307\u5b9a\u67d0\u4e2a\u7cfb\u7edf\u53c2\u6570\u7684\u503c\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>ALL_ROWS<\/strong><\/li>\n<\/ul>\n\n\n\n<p>\u4e3a\u5b9e\u73b0\u67e5\u8be2\u8bed\u53e5\u6574\u4f53\u6700\u4f18\u5316\u800c\u5f15\u5bfc\u4f18\u5316\u5668\u5236\u5b9a\u6700\u5c11\u6210\u672c\u7684\u6267\u884c\u8ba1\u5212\u3002<\/p>\n\n\n\n<p>\u4f7f\u4f18\u5316\u5668\u9009\u62e9\u4e00\u6761\u53ef\u6700\u5feb\u68c0\u7d22\u6240\u6709\u67e5\u8be2\u884c\u7684\u8def\u5f84\uff0c\u800c\u4ee3\u4ef7\u5c31\u662f\u5728\u68c0\u7d22\u4e00\u884c\u6570\u636e\u65f6\uff0c\u901f\u5ea6\u5f88\u6162\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>FIRST_ROWS<\/strong><\/li>\n<\/ul>\n\n\n\n<p>\u4e3a\u83b7\u5f97\u6700\u4f73\u54cd\u5e94\u65f6\u95f4\u800c\u5f15\u5bfc\u4f18\u5316\u5668\u5236\u5b9a\u6700\u5c11\u6210\u672c\u7684\u6267\u884c\u8ba1\u5212\u3002<\/p>\n\n\n\n<p>\u4f7f\u4f18\u5316\u5668\u9009\u62e9\u53ef\u6700\u5feb\u68c0\u7d22\u51fa\u67e5\u8be2\u7684\u7b2c\u4e00\u884c(\u6216\u6307\u5b9a\u884c)\u6570\u636e\u7684\u8def\u5f84\uff0c\u800c\u4ee3\u4ef7\u5c31\u662f\u68c0\u7d22\u5f88\u591a\u884c\u65f6\u901f\u5ea6\u5c31\u4f1a\u5f88\u6162\u3002<\/p>\n\n\n\n<p>\u5229\u7528FIRST_ROWS\u6765\u4f18\u5316\u7684\u884c\u6570\uff0c\u9ed8\u8ba4\u503c\u4e3a1\uff0c\u8fd9\u4e2a\u503c\u4ecb\u4e8e10\u52301000\u4e4b\u95f4\uff0c\u8fd9\u4e2a\u4f7f\u7528FIRST_ROWS(n)\u7684\u65b0\u65b9\u6cd5\u662f\u5b8c\u5168\u57fa\u4e8e\u4ee3\u4ef7\u7684\u65b9\u6cd5\u3002<\/p>\n\n\n\n<p>\u5b83\u5bf9n\u5f88\u654f\u611f\uff1a<\/p>\n\n\n\n<p>\u5982\u679cn\u503c\u5f88\u5c0f\uff0cCBO\u5c31\u4f1a\u751f\u6210\u5305\u542b\u5d4c\u5957\u5faa\u73af\u4ee5\u53ca\u7d22\u5f15\u67e5\u627e\u7684\u8ba1\u5212<\/p>\n\n\n\n<p>\u5982\u679cn\u5f88\u5927\uff0cCBO\u4f1a\u751f\u6210\u7531\u54c8\u5e0c\u8fde\u63a5\u548c\u5168\u8868\u626b\u63cf\u7ec4\u6210\u7684\u8ba1\u5212(\u7c7b\u4f3cALL_ROWS)<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>CHOOSE<\/strong><\/li>\n<\/ul>\n\n\n\n<p>\u4f9d\u636eSQL\u4e2d\u6240\u4f7f\u7528\u5230\u7684\u8868\u7684\u7edf\u8ba1\u4fe1\u606f\u5b58\u5728\u4e0e\u5426\uff0c\u6765\u51b3\u5b9a\u4f7f\u7528RBO\u8fd8\u662fCBO\u3002<\/p>\n\n\n\n<p>\u5728CHOOSE\u6a21\u5f0f\u4e0b\uff0c\u5982\u679c\u80fd\u591f\u53c2\u8003\u8868\u7684\u7edf\u8ba1\u4fe1\u606f\uff0c\u5219\u5c06\u6309\u7167ALL_ROWS\u65b9\u5f0f\u6267\u884c\u3002<\/p>\n\n\n\n<p>\u9664\u975e\u5728\u67e5\u8be2\u4e2d\u7684\u6240\u6709\u8868\u90fd\u6ca1\u6709\u7ecf\u8fc7\u5206\u6790\uff0c\u5426\u5219choose\u63d0\u793a\u4f1a\u5bf9\u6574\u4e2a\u67e5\u8be2\u4f7f\u7528\u57fa\u4e8e\u4ee3\u4ef7\u7684\u4f18\u5316\u3002<\/p>\n\n\n\n<p>\u5982\u679c\u5728\u591a\u8868\u8fde\u63a5\u4e2d\u6709\u4e00\u4e2a\u8868\u7ecf\u8fc7\u5206\u6790\u8fc7\uff0c\u90a3\u4e48\u5c31\u4f1a\u5bf9\u6574\u4e2a\u67e5\u8be2\u8fdb\u884c\u57fa\u4e8e\u4ee3\u4ef7\u7684\u4f18\u5316\u3002<\/p>\n\n\n\n<p>\u6ce8\uff1a&nbsp;<\/p>\n\n\n\n<p>RBO: Rule-Based Optimization \u57fa\u4e8e\u89c4\u5219\u7684\u4f18\u5316\u5668<\/p>\n\n\n\n<p>CBO: Cost-Based Optimization \u57fa\u4e8e\u4ee3\u4ef7\u7684\u4f18\u5316\u5668<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>RULE<\/li>\n<\/ul>\n\n\n\n<p>\u4f7f\u7528\u57fa\u4e8e\u89c4\u5219\u7684\u4f18\u5316\u5668\u6765\u5b9e\u73b0\u6700\u4f18\u5316\u6267\u884c\uff0c\u5373\u5f15\u5bfc\u4f18\u5316\u5668\u6839\u636e\u4f18\u5148\u987a\u5e8f\u89c4\u5219\u6765\u51b3\u5b9a\u67e5\u8be2\u6761\u4ef6\u4e2d\u6240\u4f7f\u7528\u5230\u7684\u7d22\u5f15\u6216\u8fd0\u7b97\u7b26\u7684\u6267\u884c\u987a\u5e8f\u6765\u5236\u5b9a\u6267\u884c\u8ba1\u5212\u3002<\/p>\n\n\n\n<p>\u8fd9\u4e2a\u63d0\u793a\u5f3a\u5236oracle\u4f18\u5148\u4f7f\u7528\u9884\u5b9a\u4e49\u7684\u4e00\u7ec4\u89c4\u5219\uff0c\u800c\u4e0d\u662f\u5bf9\u6570\u636e\u8fdb\u884c\u7edf\u8ba1\uff1b<\/p>\n\n\n\n<p>\u540c\u65f6\u8be5\u63d0\u793a\u8fd8\u4f1a\u4f7f\u8fd9\u4e2a\u8bed\u53e5\u907f\u514d\u4f7f\u7528\u5176\u4ed6\u63d0\u793a\uff0c\u9664\u4e86DRIVING_SITE\u548cORDERED(\u4e0d\u7ba1\u662f\u5426\u8fdb\u884c\u57fa\u4e8e\u89c4\u5219\u7684\u4f18\u5316\uff0c\u8fd9\u4e24\u4e2a\u63d0\u793a\u90fd\u53ef\u4f7f\u7528)\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">5. Hint\u5206\u7c7b \uff08\u548c\u8bbf\u95ee\u8def\u5f84\u76f8\u5173\u7684\uff09<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>FULL<\/li>\n<\/ul>\n\n\n\n<p>\u544a\u8bc9\u4f18\u5316\u5668\u901a\u8fc7\u5168\u8868\u626b\u63cf\u65b9\u5f0f\u8bbf\u95ee\u6570\u636e\u3002\u8fd9\u4e2a\u63d0\u793a\u53ea\u5bf9\u6240\u6307\u5b9a\u7684\u8868\u8fdb\u884c\u5168\u8868\u626b\u63cf\uff0c\u800c\u4e0d\u662f\u67e5\u8be2\u4e2d\u7684\u6240\u6709\u8868\u3002FULL\u63d0\u793a\u53ef\u4ee5\u6539\u5584\u6027\u80fd\u3002\u8fd9\u4e3b\u8981\u662f\u56e0\u4e3a\u5b83\u6539\u53d8\u4e86\u67e5\u8be2\u4e2d\u7684\u9a71\u52a8\u8868\uff0c\u800c\u4e0d\u662f\u56e0\u4e3a\u5168\u8868\u626b\u63cf\u3002\u5728\u4f7f\u7528\u5176\u4ed6\u67d0\u4e9b\u63d0\u793a\u65f6\uff0c\u4e5f\u5fc5\u987b\u4f7f\u7528FULL\u63d0\u793a\u3002\u53ea\u6709\u8bbf\u95ee\u6574\u4e2a\u8868\u65f6\uff0c\u624d\u53ef\u5229\u7528CACHE\u63d0\u793a\u5c06\u8868\u8fdb\u884c\u7f13\u5b58\u3002\u5e76\u884c\u7ec4\u4e2d\u7684\u67d0\u4e9b\u63d0\u793a\u4e5f\u5fc5\u987b\u4f7f\u7528\u5168\u8868\u626b\u63cf\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>CLUSTER<\/li>\n<\/ul>\n\n\n\n<p>\u5f15\u5bfc\u4f18\u5316\u5668\u901a\u8fc7\u626b\u63cf\u805a\u7c07\u7d22\u5f15\u6765\u4ece\u7d22\u5f15\u8868\u4e2d\u8bfb\u53d6\u6570\u636e\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>HASH<\/li>\n<\/ul>\n\n\n\n<p>\u5f15\u5bfc\u4f18\u5316\u5668\u6309\u7167\u54c8\u5e0c\u626b\u63cf\u7684\u65b9\u5f0f\u4ece\u8868\u4e2d\u8bfb\u53d6\u6570\u636e\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>INDEX<\/li>\n<\/ul>\n\n\n\n<p>\u544a\u8bc9\u4f18\u5316\u5668\u5bf9\u6307\u5b9a\u8868\u901a\u8fc7\u7d22\u5f15\u7684\u65b9\u5f0f\u8bbf\u95ee\u6570\u636e\u3002\u5f53\u8bbf\u95ee\u6570\u636e\u4f1a\u5bfc\u81f4\u7ed3\u679c\u96c6\u4e0d\u5b8c\u6574\u65f6\uff0c\u4f18\u5316\u5668\u5c06\u5ffd\u7565\u8fd9\u4e2aHint\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>NO_INDEX<\/li>\n<\/ul>\n\n\n\n<p>\u544a\u8bc9\u4f18\u5316\u5668\u5bf9\u6307\u5b9a\u8868\u4e0d\u5141\u8bb8\u4f7f\u7528\u7d22\u5f15\u3002\u8fd9\u4e2a\u63d0\u793a\u4f1a\u7981\u6b62\u4f18\u5316\u5668\u4f7f\u7528\u6307\u5b9a\u7d22\u5f15\u3002\u53ef\u4ee5\u5728\u5220\u9664\u4e0d\u5fc5\u8981\u7684\u7d22\u5f15\u4e4b\u524d\u5728\u8bb8\u591a\u67e5\u8be2\u4e2d\u7981\u6b62\u7d22\u5f15\u3002\u5982\u679c\u4f7f\u7528\u4e86NO_INDEX\uff0c\u4f46\u662f\u6ca1\u6709\u6307\u5b9a\u4efb\u4f55\u7d22\u5f15\uff0c\u5219\u4f1a\u6267\u884c\u5168\u8868\u626b\u63cf\u3002\u5982\u679c\u5bf9\u67d0\u4e2a\u7d22\u5f15\u540c\u65f6\u4f7f\u7528\u4e86NO_INDEX\u548c\u4f1a\u4e4b\u4ea7\u751f\u51b2\u7a81\u7684\u63d0\u793a(\u5982INDEX)\uff0c\u8fd9\u65f6\u4e24\u4e2a\u63d0\u793a\u90fd\u4f1a\u88ab\u5ffd\u7565\u6389\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>INDEX_ASC<\/li>\n<\/ul>\n\n\n\n<p>\u5229\u7528\u7d22\u5f15\u4ece\u8868\u4e2d\u8bfb\u53d6\u6570\u636e\u65f6\uff0c\u5f15\u5bfc\u4f18\u5316\u5668\u5bf9\u63d0\u793a\u4e2d\u6240\u6307\u5b9a\u7d22\u5f15\u7684\u7d22\u5f15\u5217\u503c\u6309\u7167\u5347\u5e8f\u4f7f\u7528\u8303\u56f4\u626b\u63cf\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>INDEX_COMBINE<\/li>\n<\/ul>\n\n\n\n<p>\u544a\u8bc9\u4f18\u5316\u5668\u5f3a\u5236\u9009\u62e9\u4f4d\u56fe\u7d22\u5f15\u3002\u8fd9\u4e2a\u63d0\u793a\u4f1a\u4f7f\u4f18\u5316\u5668\u5408\u5e76\u8868\u4e0a\u7684\u591a\u4e2a\u4f4d\u56fe\u7d22\u5f15\uff0c\u800c\u4e0d\u662f\u9009\u62e9\u5176\u4e2d\u6700\u597d\u7684\u7d22\u5f15(\u8fd9\u662fINDEX\u63d0\u793a\u7684\u7528\u9014)\u3002\u8fd8\u53ef\u4ee5\u4f7f\u7528index_combine\u6307\u5b9a\u5355\u4e2a\u7d22\u5f15(\u5bf9\u4e8e\u6307\u5b9a\u4f4d\u56fe\u7d22\u5f15\uff0c\u8be5\u63d0\u793a\u4f18\u5148\u4e8eINDEX\u63d0\u793a)\u3002\u5bf9\u4e8eB\u6811\u7d22\u5f15\uff0c\u53ef\u4ee5\u4f7f\u7528AND_EQUAL\u63d0\u793a\u800c\u4e0d\u662f\u8fd9\u4e2a\u63d0\u793a\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>INDEX_JOIN<\/li>\n<\/ul>\n\n\n\n<p>\u7d22\u5f15\u5173\u8054\uff0c\u5f53\u8c13\u8bcd\u4e2d\u5f15\u7528\u7684\u5217\u4e0a\u90fd\u6709\u7d22\u5f15\u7684\u65f6\u5019\uff0c\u53ef\u4ee5\u901a\u8fc7\u7d22\u5f15\u5173\u8054\u7684\u65b9\u5f0f\u6765\u8bbf\u95ee\u6570\u636e\u3002\u8fd9\u4e2a\u63d0\u793a\u53ef\u4ee5\u5c06\u540c\u4e00\u4e2a\u8868\u7684\u5404\u4e2a\u4e0d\u540c\u7d22\u5f15\u8fdb\u884c\u5408\u5e76\uff0c\u8fd9\u6837\u5c31\u53ea\u9700\u8981\u8bbf\u95ee\u8fd9\u4e9b\u7d22\u5f15\u5c31\u53ef\u4ee5\u4e86\uff0c\u8282\u7701\u4e86\u56de\u8868\u67e5\u8be2\u7684\u65f6\u95f4\u3002\u4f46\u53ea\u80fd\u5728\u57fa\u4e8e\u4ee3\u4ef7\u7684\u4f18\u5316\u5668\u4e2d\u4f7f\u7528\u8be5\u63d0\u793a\u3002\u8fd9\u4e2a\u63d0\u793a\u4e0d\u4ec5\u5141\u8bb8\u53ea\u8bbf\u95ee\u8868\u4e0a\u7684\u7d22\u5f15\uff0c\u8fd9\u6837\u53ef\u4ee5\u626b\u63cf\u66f4\u5c11\u7684\u4ee3\u7801\u5757\uff0c\u5e76\u4e14\u5b83\u6bd4\u4f7f\u7528\u7d22\u5f15\u5e76\u901a\u8fc7rowid\u626b\u63cf\u6574\u4e2a\u8868\u5feb5\u500d\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>INDEX_DESC<\/li>\n<\/ul>\n\n\n\n<p>\u5229\u7528\u7d22\u5f15\u4ece\u8868\u4e2d\u8bfb\u53d6\u6570\u636e\u65f6\uff0c\u5f15\u5bfc\u4f18\u5316\u5668\u5bf9\u63d0\u793a\u4e2d\u6240\u6307\u5b9a\u7d22\u5f15\u7684\u7d22\u5f15\u5217\u503c\u6309\u7167\u964d\u5e8f\u4f7f\u7528\u8303\u56f4\u626b\u63cf\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>INDEX_FFS<\/li>\n<\/ul>\n\n\n\n<p>\u544a\u8bc9\u4f18\u5316\u5668\u4ee5INDEX FFS(index fast full scan)\u7684\u65b9\u5f0f\u8bbf\u95ee\u6570\u636e\u3002INDEX_FFS\u63d0\u793a\u4f1a\u6267\u884c\u4e00\u6b21\u7d22\u5f15\u7684\u5feb\u901f\u5168\u5c40\u626b\u63cf\u3002\u8fd9\u4e2a\u63d0\u793a\u53ea\u8bbf\u95ee\u7d22\u5f15\uff0c\u800c\u4e0d\u662f\u5bf9\u5e94\u7684\u8868\u3002\u53ea\u6709\u67e5\u8be2\u9700\u8981\u68c0\u7d22\u7684\u4fe1\u606f\u90fd\u5728\u7d22\u5f15\u4e0a\u65f6\uff0c\u624d\u4f7f\u7528\u8fd9\u4e2a\u63d0\u793a\u3002\u7279\u522b\u5728\u8868\u6709\u5f88\u591a\u5217\u65f6\uff0c\u4f7f\u7528\u8be5\u63d0\u793a\u53ef\u4ee5\u6781\u5927\u5730\u6539\u5584\u6027\u80fd\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>INDEX_SS<\/li>\n<\/ul>\n\n\n\n<p>\u5f3a\u5236\u4f7f\u7528index skip scan\u7684\u65b9\u5f0f\u8bbf\u95ee\u7d22\u5f15\u3002\u5f53\u5728\u4e00\u4e2a\u8054\u5408\u7d22\u5f15\u4e2d\uff0c\u67d0\u4e9b\u8c13\u8bcd\u6761\u4ef6\u5e76\u4e0d\u5728\u8054\u5408\u7d22\u5f15\u7684\u7b2c\u4e00\u5217\u65f6(\u6216\u8005\u8c13\u8bcd\u5e76\u4e0d\u5728\u8054\u5408\u7d22\u5f15\u7684\u7b2c\u4e00\u5217\u65f6)\uff0c\u53ef\u4ee5\u901a\u8fc7index skip scan\u6765\u8bbf\u95ee\u7d22\u5f15\u83b7\u5f97\u6570\u636e\u3002\u5f53\u8054\u5408\u7d22\u5f15\u7b2c\u4e00\u5217\u7684\u552f\u4e00\u503c\u5f88\u5c11\u65f6\uff0c\u4f7f\u7528\u8fd9\u79cd\u65b9\u5f0f\u6bd4\u5168\u8868\u626b\u63cf\u7684\u65b9\u5f0f\u6548\u7387\u8981\u9ad8\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">6. Hint\u5206\u7c7b\uff08\u548c\u67e5\u8be2\u8f6c\u6362\u76f8\u5173\u7684\uff09<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>USE_CONCAT<\/li>\n<\/ul>\n\n\n\n<p>\u5c06\u542b\u6709\u591a\u4e2aOR\u6216\u8005IN\u8fd0\u7b97\u7b26\u6240\u8fde\u63a5\u8d77\u6765\u7684\u67e5\u8be2\u8bed\u53e5\u5206\u89e3\u4e3a\u591a\u4e2a\u5355\u4e00\u67e5\u8be2\u8bed\u53e5\uff0c\u5e76\u4e3a\u6bcf\u4e2a\u5355\u4e00\u67e5\u8be2\u8bed\u53e5\u9009\u62e9\u6700\u4f18\u5316\u67e5\u8be2\u8def\u5f84\uff0c\u7136\u540e\u518d\u5c06\u8fd9\u4e9b\u6700\u4f18\u5316\u67e5\u8be2\u8def\u5f84\u7ed3\u5408\u5728\u4e00\u8d77\uff0c\u4ee5\u5b9e\u73b0\u6574\u4f53\u67e5\u8be2\u8bed\u53e5\u7684\u6700\u4f18\u5316\u76ee\u7684\u3002\u53ea\u6709\u5728\u9a71\u52a8\u67e5\u8be2\u6761\u4ef6\u4e2d\u5305\u542bOR\u7684\u65f6\u5019\uff0c\u624d\u53ef\u4ee5\u4f7f\u7528\u8be5\u63d0\u793a\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>NO_EXPAND<\/li>\n<\/ul>\n\n\n\n<p>\u5f15\u5bfc\u4f18\u5316\u5668\u4e0d\u8981\u4e3a\u4f7f\u7528OR\u8fd0\u7b97\u7b26\u53f7(\u6216IN\u8fd0\u7b97\u7b26)\u7684\u6761\u4ef6\u5236\u5b9a\u76f8\u4e92\u7ed3\u5408\u7684\u6267\u884c\u8ba1\u5212\u3002\u6b63\u597d\u548cUSE_CONCAT\u76f8\u53cd\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>REWRITE<\/li>\n<\/ul>\n\n\n\n<p>\u5f53\u8868\u8fde\u63a5\u7684\u5bf9\u8c61\u662f\u6570\u636e\u91cf\u6bd4\u8f83\u5927\u7684\u8868\u6216\u8005\u9700\u8981\u83b7\u5f97\u4f7f\u7528\u7edf\u8ba1\u51fd\u6570\u5904\u7406\u8fc7\u7684\u7ed3\u679c\u65f6\uff0c\u4e3a\u4e86\u63d0\u9ad8\u6267\u884c\u901f\u5ea6\u53ef\u9884<strong>\u5148\u521b\u5efa\u7269\u5316\u89c6\u56fe<\/strong>\u3002<\/p>\n\n\n\n<p>\u5f53\u7528\u6237\u8981\u6c42\u67e5\u8be2\u67d0\u4e2a\u67e5\u8be2\u8bed\u53e5\u65f6\uff0c\u4f18\u5316\u5668\u4f1a\u5728\u4ece\u8868\u4e2d\u548c\u4ece\u7269\u5316\u89c6\u56fe\u4e2d\u8bfb\u53d6\u6570\u636e\u7684\u4e24\u79cd\u65b9\u6cd5\u4e2d\u9009\u62e9\u4e00\u4e2a\u66f4\u6709\u6548\u7684\u65b9\u6cd5\u6765\u8bfb\u53d6\u6570\u636e\u3002\u8be5\u6267\u884c\u65b9\u6cd5\u79f0\u4e4b\u4e3a\u67e5\u8be2\u91cd\u5199\u3002\u4f7f\u7528REWRITE\u63d0\u793a\u5f15\u5bfc\u4f18\u5316\u5668\u6309\u7167\u8be5\u65b9\u5f0f\u6267\u884c\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>MERGE<\/li>\n<\/ul>\n\n\n\n<p>\u4e3a\u4e86\u80fd\u4ee5\u6700\u4f18\u65b9\u5f0f\u4ece\u89c6\u56fe\u6216\u8005\u5d4c\u5957\u89c6\u56fe\u4e2d\u8bfb\u53d6\u6570\u636e\uff0c\u901a\u8fc7\u53d8\u6362\u67e5\u8be2\u8bed\u53e5\u6765\u76f4\u63a5\u8bfb\u53d6\u89c6\u56fe\u4f7f\u7528\u7684\u57fa\u8868\u6570\u636e\uff0c\u8be5\u8fc7\u7a0b\u88ab\u79f0\u4e4b\u4e3a\u89c6\u56fe\u5408\u5e76\u3002\u4e0d\u540c\u7684\u60c5\u51b5\u5176\u5177\u4f53\u4f7f\u7528\u7c7b\u578b\u4e5f\u6709\u6240\u4e0d\u540c\u3002\u8be5\u63d0\u793a\u4e3b\u8981\u5728\u89c6\u56fe\u672a\u53d1\u751f\u5408\u5e76\u65f6\u88ab\u4f7f\u7528\u3002\u5c24\u5176\u662f<strong>\u5bf9\u6bd4\u8f83\u590d\u6742\u7684\u89c6\u56fe\u6216\u8005\u5d4c\u5957\u89c6\u56fe(\u6bd4\u5982\u4f7f\u7528\u4e86GROUP BY\u6216DISTINC\u7684\u89c6\u56fe)\u4f7f\u7528\u8be5\u63d0\u793a\uff0c\u6709\u65f6\u4f1a\u53d6\u5f97\u975e\u5e38\u597d\u7684\u6548\u679c\u3002<\/strong><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>UNNEST<\/li>\n<\/ul>\n\n\n\n<p>\u63d0\u793a\u4f18\u5316\u5668\u5c06\u5b50\u67e5\u8be2\u8f6c\u6362\u4e3a\u8fde\u63a5\u7684\u65b9\u5f0f\u3002\u4e5f\u5c31\u662f\u5f15\u5bfc\u4f18\u5316\u5668\u5408\u5e76\u5b50\u67e5\u8be2\u548c\u4e3b\u67e5\u8be2\u5e76\u4e14\u5c06\u5176\u5411\u8fde\u63a5\u7c7b\u578b\u8f6c\u6362\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>NO_UNNEST<\/li>\n<\/ul>\n\n\n\n<p>\u5f15\u5bfc\u4f18\u5316\u5668\u8ba9\u5b50\u67e5\u8be2\u80fd\u591f\u72ec\u7acb\u5730\u6267\u884c\u5b8c\u6bd5\u4e4b\u540e\u518d\u8ddf\u5916\u56f4\u7684\u67e5\u8be2\u505aFILTER\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>PUSH_PRED<\/li>\n<\/ul>\n\n\n\n<p>\u4f7f\u7528\u8be5\u63d0\u793a\u53ef\u4ee5\u5c06\u89c6\u56fe\u6216\u5d4c\u5957\u89c6\u56fe\u4ee5\u5916\u7684\u67e5\u8be2\u6761\u4ef6\u63a8\u5165\u5230\u89c6\u56fe\u4e4b\u5185\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>NO_PUSH_PRED<\/li>\n<\/ul>\n\n\n\n<p>\u4f7f\u7528\u8be5\u63d0\u793a\u786e\u4fdd\u89c6\u56fe\u6216\u5d4c\u5957\u89c6\u56fe\u4ee5\u5916\u7684\u67e5\u8be2\u6761\u4ef6\u4e0d\u88ab\u63a8\u5165\u5230\u89c6\u56fe\u5185\u90e8\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>PUSH_SUBQ<\/li>\n<\/ul>\n\n\n\n<p>\u4f7f\u7528\u8be5\u63d0\u793a\u5f15\u5bfc\u4f18\u5316\u5668\u4e3a\u4e0d\u80fd\u5408\u5e76\u7684\u5b50\u67e5\u8be2\u5236\u5b9a\u6267\u884c\u8ba1\u5212\u3002\u4e0d\u80fd\u5408\u5e76\u7684\u5b50\u67e5\u8be2\u88ab\u4f18\u5148\u6267\u884c\u4e4b\u540e\uff0c\u8be5\u5b50\u67e5\u8be2\u7684\u6267\u884c\u7ed3\u679c\u5c06\u626e\u6f14\u7f29\u51cf\u4e3b\u67e5\u8be2\u6570\u636e\u67e5\u8be2\u8303\u56f4\u7684\u63d0\u4f9b\u8005\u89d2\u8272\u3002\u901a\u5e38\u5728\u65e0\u6cd5\u6267\u884c\u5b50\u67e5\u8be2\u5408\u5e76\u7684\u60c5\u51b5\u4e0b\uff0c\u5b50\u67e5\u8be2\u626e\u6f14\u7684\u90fd\u662f\u68c0\u9a8c\u8005\u89d2\u8272\uff0c\u6240\u4ee5\u5b50\u67e5\u8be2\u4e00\u822c\u88ab\u653e\u5728\u6700\u540e\u6267\u884c\u3002\u5728\u65e0\u6cd5\u88ab\u5408\u5e76\u7684\u5b50\u67e5\u8be2\u62e5\u6709\u8f83\u5c11\u7684\u7ed3\u679c\u884c\uff0c\u6216\u8005\u8be5\u5b50\u67e5\u8be2\u53ef\u4ee5\u7f29\u51cf\u4e3b\u67e5\u8be2\u67e5\u8be2\u8303\u56f4\u7684\u60c5\u51b5\u4e0b\uff0c\u53ef\u4ee5\u4f7f\u7528\u8be5\u63d0\u793a\u5f15\u5bfc\u4f18\u5316\u5668\u6700\u5927\u7a0b\u5ea6\u5730\u5c06\u8be5\u5b50\u67e5\u8be2\u653e\u5728\u524d\u9762\u6267\u884c\uff0c\u4ee5\u63d0\u9ad8\u6267\u884c\u901f\u5ea6\u3002\u4f46\u5982\u679c\u5b50\u67e5\u8be2\u6267\u884c\u7684\u662f\u8fdc\u7a0b\u8868\u6216\u8005\u6392\u5e8f\u5408\u5e76\u8fde\u63a5\u7684\u4e00\u90e8\u5206\u8fde\u63a5\u7ed3\u679c\uff0c\u5219\u8be5\u63d0\u793a\u5c06\u4e0d\u8d77\u4efb\u4f55\u4f5c\u7528\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>NO_PUSH_SUBQ<\/li>\n<\/ul>\n\n\n\n<p>\u4f7f\u7528\u8be5\u63d0\u793a\u5c06\u5f15\u5bfc\u4f18\u5316\u5668\u5c06\u4e0d\u80fd\u5b9e\u73b0\u5408\u5e76\u7684\u5b50\u67e5\u8be2\u653e\u5728\u6700\u540e\u6267\u884c\u3002\u5728\u5b50\u67e5\u8be2\u65e0\u6cd5\u7f29\u51cf\u4e3b\u67e5\u8be2\u7684\u67e5\u8be2\u8303\u56f4\uff0c\u6216\u8005\u6267\u884c\u5b50\u67e5\u8be2\u5f00\u9500\u8f83\u5927\u7684\u60c5\u51b5\u4e0b\uff0c\u5c06\u8fd9\u6837\u7684\u5b50\u67e5\u8be2\u653e\u5728\u6700\u540e\u6267\u884c\u53ef\u4ee5\u5728\u67d0\u79cd\u7a0b\u5ea6\u4e0a\u63d0\u9ad8\u6574\u4f53\u7684\u6267\u884c\u6548\u7387\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5c3d\u53ef\u80fd\u5730\u4f7f\u7528\u5176\u4ed6\u67e5\u8be2\u6761\u4ef6\u6700\u5927\u7a0b\u5ea6\u5730\u7f29\u51cf\u67e5\u8be2\u8303\u56f4\u4e4b\u540e\uff0c\u518d\u6267\u884c\u5b50\u67e5\u8be2\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">7. Hint\u5206\u7c7b\uff08\u548c\u8868\u8fde\u63a5\u987a\u5e8f\u76f8\u5173\u7684\uff09<\/h2>\n\n\n\n<p>\u8fd9\u4e9b\u63d0\u793a\u53ef\u4ee5\u8c03\u6574\u8868\u8fde\u63a5\u7684\u987a\u5e8f\u3002\u8c03\u6574\u8868\u8fde\u63a5\u7684\u987a\u5e8f\u5e76\u4e0d\u662f\u53ea\u80fd\u4f7f\u7528\u8fd9\u4e9b\u63d0\u793a\uff0c\u5728\u5d4c\u5957\u5faa\u73af\u8fde\u63a5\u65b9\u5f0f\u4e2d\u4e5f\u53ef\u4ee5\u8ba9\u63d0\u793a\u6765\u5f15\u5bfc\u4f18\u5316\u5668\u4f7f\u7528\u7531\u9a71\u52a8\u67e5\u8be2\u6761\u4ef6\u6240\u521b\u5efa\u7684\u7d22\u5f15\u3002\u7136\u800c\uff0c\u8be5\u65b9\u6cd5\u53ea\u6709\u5728\u4f7f\u7528\u7684\u7d22\u5f15\u548c\u8868\u8fde\u63a5\u987a\u5e8f\u540c\u65f6\u88ab\u8c03\u6574\u7684\u60c5\u51b5\u4e0b\u624d\u6bd4\u8f83\u6709\u6548\u3002\u4e00\u822c\u800c\u8a00\uff0c\u8fd9\u4e9b\u63d0\u793a\u4e3b\u8981\u5728\u6267\u884c\u591a\u8868\u8fde\u63a5\u548c\u8868\u4e4b\u95f4\u7684\u8fde\u63a5\u987a\u5e8f\u6bd4\u8f83\u6df7\u4e71\u7684\u60c5\u51b5\u4e0b\u624d\u4f7f\u7528\uff0c\u4e5f\u5728\u6392\u5e8f\u5408\u5e76\u8fde\u63a5\u6216\u54c8\u5e0c\u8fde\u63a5\u65b9\u5f0f\u4e0b\uff0c\u4e3a\u5f15\u5bfc\u4f18\u5316\u5668\u4f18\u5148\u6267\u884c\u6570\u636e\u91cf\u6bd4\u8f83\u5c11\u5f97\u8868\u65f6\u4f7f\u7528\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>LEADING<\/li>\n<\/ul>\n\n\n\n<p>\u5728\u4e00\u4e2a\u591a\u8868\u5173\u8054\u7684\u67e5\u8be2\u4e2d\uff0c\u8fd9\u4e2aHint\u6307\u5b9a\u7531\u54ea\u4e2a\u8868\u4f5c\u4e3a\u9a71\u52a8\u8868\uff0c\u5373\u544a\u8bc9\u4f18\u5316\u5668\u9996\u5148\u8981\u8bbf\u95ee\u90a3\u4e2a\u8868\u4e0a\u7684\u6570\u636e\u3002<\/p>\n\n\n\n<p>\u5f15\u5bfc\u4f18\u5316\u5668\u4f7f\u7528LEADING\u6307\u5b9a\u7684\u8868\u4f5c\u4e3a\u8868\u8fde\u63a5\u987a\u5e8f\u4e2d\u7684\u7b2c\u4e00\u4e2a\u8868\u3002\u8be5\u63d0\u793a\u65e2\u4e0eFROM\u4e2d\u6240\u63cf\u8ff0\u7684\u8868\u7684\u987a\u5e8f\u65e0\u5173\uff0c\u4e5f\u4e0e\u4f5c\u4e3a\u8c03\u6574\u8868\u8fde\u63a5\u987a\u5e8f\u7684ORDERED\u63d0\u793a\u4e0d\u540c\uff0c\u5e76\u4e14\u5728\u4f7f\u7528\u8be5\u63d0\u793a\u65f6\u5e76\u4e0d\u9700\u8981\u8c03\u6574FROM\u4e2d\u6240\u63cf\u8ff0\u7684\u8868\u7684\u987a\u5e8f\u3002\u5f53\u8be5\u63d0\u793a\u4e0eORDERED\u63d0\u793a\u540c\u65f6\u4f7f\u7528\u65f6\uff0c\u8be5\u63d0\u793a\u88ab\u5ffd\u7565\u3002<\/p>\n\n\n\n<p>\u8fd9\u4e2a\u63d0\u793a\u7c7b\u4f3cORDERED\u63d0\u793a\uff0c\u5b83\u5141\u8bb8\u6307\u5b9a\u9a71\u52a8\u67e5\u8be2\u7684\u8868\uff0c\u7136\u540e\u7531\u4f18\u5316\u5668\u6765\u5224\u65ad\u4e0b\u4e00\u4e2a\u8981\u8bbf\u95ee\u7684\u8868\u3002\u5982\u679c\u4f7f\u7528\u8fd9\u4e2a\u63d0\u793a\u6307\u5b9a\u591a\u5f20\u8868\uff0c\u90a3\u4e48\u5c31\u53ef\u4ee5\u5ffd\u7565\u8fd9\u4e2a\u63d0\u793a\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>ORDERED<\/li>\n<\/ul>\n\n\n\n<p>\u5f15\u5bfc\u4f18\u5316\u5668\u6309\u7167FROM\u4e2d\u6240\u63cf\u8ff0\u7684\u8868\u7684\u987a\u5e8f\u6267\u884c\u8fde\u63a5\u3002\u5982\u679c\u548cLEADING\u63d0\u793a\u88ab\u4e00\u8d77\u4f7f\u7528\uff0c\u5219LEADING\u63d0\u793a\u5c06\u88ab\u5ffd\u7565\u3002\u7531\u4e8eORDERED\u53ea\u80fd\u8c03\u6574\u8868\u8fde\u63a5\u7684\u987a\u5e8f\u5e76\u4e0d\u80fd\u6539\u53d8\u8868\u8fde\u63a5\u7684\u65b9\u5f0f\uff0c\u6240\u4ee5\u4e3a\u4e86\u6539\u53d8\u8868\u7684\u8fde\u63a5\u65b9\u5f0f\uff0c\u7ecf\u5e38\u5c06USE_NL\u3001USE_MERGE\u63d0\u793a\u4e0eORDERED\u63d0\u793a\u653e\u5728\u4e00\u8d77\u4f7f\u7528\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">8. Hint\u5206\u7c7b\uff08\u548c\u8868\u8fde\u63a5\u64cd\u4f5c\u76f8\u5173\u7684)<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>USE_NL<\/li>\n<\/ul>\n\n\n\n<p>\u4f7f\u7528\u8be5\u63d0\u793a\u5f15\u5bfc\u4f18\u5316\u5668\u6309\u7167\u5d4c\u5957\u5faa\u73af\u8fde\u63a5\u65b9\u5f0f\u6267\u884c\u8868\u8fde\u63a5\u3002\u5b83\u53ea\u662f\u6307\u51fa\u8868\u8fde\u63a5\u7684\u65b9\u5f0f\uff0c\u5bf9\u4e8e\u8868\u8fde\u63a5\u987a\u5e8f\u4e0d\u4f1a\u6709\u4efb\u4f55\u5f71\u54cd\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>USE_MERGE<\/li>\n<\/ul>\n\n\n\n<p>\u5f15\u5bfc\u4f18\u5316\u5668\u6309\u7167\u6392\u5e8f\u5408\u5e76\u8fde\u63a5\u65b9\u5f0f\u6267\u884c\u8fde\u63a5\u3002\u5728\u6709\u5fc5\u8981\u7684\u60c5\u51b5\u4e0b\uff0c\u63a8\u8350\u5c06\u8be5\u63d0\u793a\u4e0eORDERED\u63d0\u793a\u4e00\u8d77\u4f7f\u7528\u3002\u63d0\u793a\u901a\u5e38\u7528\u4e8e\u83b7\u5f97\u67e5\u8be2\u7684\u6700\u4f73\u541e\u5410\u91cf\u3002\u5047\u8bbe\u5c06\u4e24\u4e2a\u8868\u8fde\u63a5\u5728\u4e00\u8d77\uff0c\u4ece\u6bcf\u4e2a\u8868\u8fd4\u56de\u7684\u884c\u96c6\u5c06\u88ab\u6392\u5e8f\uff0c\u7136\u540e\u518d\u88ab\u5408\u5e76(\u4e5f\u5c31\u662f\u5408\u5e76\u6392\u5e8f)\uff0c\u4ece\u800c\u7ec4\u6210\u6700\u7ec8\u7684\u7ed3\u679c\u96c6\u3002\u7531\u4e8e\u6bcf\u4e2a\u884c\u5148\u88ab\u6392\u5e8f\u4e4b\u540e\u624d\u8fdb\u884c\u5408\u5e76\uff0c\u6240\u4ee5\u5728\u7ed9\u5b9a\u67e5\u8be2\u4e2d\u68c0\u7d22\u6240\u6709\u884c\u65f6\uff0c\u901f\u5ea6\u5c06\u4f1a\u6700\u5feb\u3002\u5982\u679c\u9700\u8981\u4ee5\u6700\u5feb\u901f\u5ea6\u8fd4\u56de\u7b2c\u4e00\u884c\uff0c\u5c31\u5e94\u8be5\u4f7f\u7528USE_NL\u63d0\u793a\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>USE_HASH<\/li>\n<\/ul>\n\n\n\n<p>\u8be5\u63d0\u793a\u5f15\u5bfc\u4f18\u5316\u5668\u6309\u7167\u54c8\u5e0c\u8fde\u63a5\u65b9\u5f0f\u6267\u884c\u8fde\u63a5\u3002\u5728\u6267\u884c\u54c8\u5e0c\u8fde\u63a5\u65f6\uff0c\u5982\u679c\u7531\u4e8e\u67d0\u4e00\u8fb9\u7684\u8868\u6bd4\u8f83\u5c0f\uff0c\u4ece\u800c\u53ef\u4ee5\u5728\u5185\u5b58\u4e2d\u5b9e\u73b0\u54c8\u5e0c\u8fde\u63a5\uff0c\u90a3\u4e48\u5c31\u80fd\u591f\u83b7\u5f97\u975e\u5e38\u597d\u7684\u6267\u884c\u901f\u5ea6\u3002\u7531\u4e8e\u5728\u5927\u90e8\u5206\u60c5\u51b5\u4e0b\u4f18\u5316\u5668\u4f1a\u901a\u8fc7\u5bf9\u7edf\u8ba1\u4fe1\u606f\u7684\u5206\u6790\u6765\u51b3\u5b9aBuild Input\u548cProve Input\uff0c\u6240\u4ee5\u5efa\u8bae\u4e0d\u8981\u4f7f\u7528ORDERED\u63d0\u793a\u968f\u610f\u6539\u53d8\u8868\u7684\u8fde\u63a5\u987a\u5e8f\u3002\u4f46\u662f\u5f53\u4f18\u5316\u5668\u6ca1\u80fd\u505a\u51fa\u6b63\u786e\u5224\u65ad\u65f6\uff0c\u6216\u8005\u50cf\u4ece\u5d4c\u5957\u89c6\u56fe\u4e2d\u6240\u83b7\u5f97\u7684\u7ed3\u679c\u96c6\u5408\u90a3\u6837\u4e0d\u5177\u5907\u7edf\u8ba1\u4fe1\u606f\u65f6\uff0c\u53ef\u4ee5\u4f7f\u7528\u8be5\u63d0\u793a\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">\u00a09. \u548c\u5e76\u884c\u76f8\u5173\u7684<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>PARALLEL<\/li>\n<\/ul>\n\n\n\n<p>\u6307\u5b9aSQL\u6267\u884c\u7684\u5e76\u884c\u5ea6\uff0c\u8fd9\u4e2a\u503c\u5c06\u4f1a\u8986\u76d6\u8868\u81ea\u8eab\u8bbe\u5b9a\u7684\u5e76\u884c\u5ea6\u3002<\/p>\n\n\n\n<p>\u5982\u679c\u8fd9\u4e2a\u503c\u4e3adefault\uff0cCBO\u4f7f\u7528\u7cfb\u7edf\u53c2\u6570\u3002<\/p>\n\n\n\n<p>\u4ece\u8868\u4e2d\u8bfb\u53d6\u5927\u91cf\u6570\u636e\u548c\u6267\u884cDML\u64cd\u4f5c\u65f6\u4f7f\u7528\u8be5\u63d0\u793a\u6765\u6307\u5b9aSQL\u7684\u5e76\u884c\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p>\u4e00\u822c\u60c5\u51b5\u4e0b\u9700\u8981\u5728\u8be5\u63d0\u793a\u4e2d\u6307\u5b9a\u5c06\u8981\u4f7f\u7528\u7684\u5e76\u884c\u7ebf\u7a0b\u4e2a\u6570,\u5982\u679c\u5728\u8be5\u63d0\u793a\u4e2d\u6ca1\u6709\u6307\u5b9a\u5e76\u884c\u5ea6\u7684\u4e2a\u6570\uff0c\u5219\u4f18\u5316\u5668\u5c06\u4f7f\u7528PARALLEL_THREADS_PER_CPU\u53c2\u6570\u6240\u6307\u5b9a\u7684\u503c\u8fdb\u884c\u81ea\u52a8\u8ba1\u7b97\u3002<\/p>\n\n\n\n<p>\u5982\u679c\u5728\u5b9a\u4e49\u8868\u65f6\u6307\u5b9a\u4e86PARALLEL\uff0c\u90a3\u4e48\u5728\u80fd\u591f\u4f7f\u7528\u5e76\u884c\u64cd\u4f5c\u7684\u60c5\u51b5\u4e0b\uff0c\u5373\u4f7f\u6ca1\u6709\u4f7f\u7528\u8be5\u63d0\u793a\uff0c\u4f18\u5316\u5668\u4e5f\u4f1a\u6309\u7167\u6307\u5b9a\u7684\u5e76\u884c\u7ea7\u522b\u9009\u62e9\u5e76\u884c\u64cd\u4f5c\u3002<\/p>\n\n\n\n<p>\u4f46\u662f\u5982\u679c\u60f3\u5728DELETE\u3001INSERT\u3001UPDATE\u3001MERGE\u7b49DML\u64cd\u4f5c\u4e2d\u4f7f\u7528\u5e76\u884c\u64cd\u4f5c\uff0c\u5219\u5fc5\u987b\u8981\u5728\u4f1a\u8bdd\u4e2d\u8bbe\u7f6eALTER SESSION ENABLE PARALLEL DML\u3002<\/p>\n\n\n\n<p>\u5728\u67d0\u4e2a\u4f1a\u8bdd\u4e2d\u6240\u8bbe\u7f6e\u7684\u5e76\u884c\u7ea7\u522b\u4e5f\u53ef\u4ee5\u88ab\u5f15\u7528\u5728\u5185\u90e8\u7684GROUP BY\u6216\u8005\u6392\u5e8f\u64cd\u4f5c\u4e2d\u3002\u5728\u5e76\u884c\u64cd\u4f5c\u4e2d\u5982\u679c\u51fa\u73b0\u4e86\u67d0\u4e2a\u9650\u5236\u8981\u7d20\uff0c\u5219\u8be5\u63d0\u793a\u5c06\u88ab\u5ffd\u7565\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>NOPARALLEL\/NO_PARALLEL<\/li>\n<\/ul>\n\n\n\n<p>\u5728SQL\u8bed\u53e5\u7981\u6b62\u4f7f\u7528\u5e76\u884c\u3002\u5728\u6709\u4e9b\u7248\u672c\u4e2d\u7528NO_PARALLEL\u63d0\u793a\u6765\u4ee3\u66ffNOPARALLEL\u63d0\u793a\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>PQ_DISTRIBUTE<\/li>\n<\/ul>\n\n\n\n<p>\u4e3a\u4e86\u63d0\u9ad8\u5e76\u884c\u8fde\u63a5\u7684\u6267\u884c\u901f\u5ea6\uff0c\u4f7f\u7528\u8be5\u63d0\u793a\u6765\u5b9a\u4e49\u4f7f\u7528\u4f55\u79cd\u65b9\u6cd5\u5728\u4e3b\u4ece\u8fdb\u7a0b\u4e4b\u95f4(\u4f8b\u5982\u751f\u4ea7\u8005\u8fdb\u7a0b\u548c\u6d88\u8d39\u8005\u8fdb\u7a0b)\u5206\u914d\u5404\u8fde\u63a5\u8868\u7684\u6570\u636e\u884c\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>PARALLEL_INDEX<\/li>\n<\/ul>\n\n\n\n<p>\u4e3a\u4e86\u6309\u7167\u5e76\u884c\u64cd\u4f5c\u7684\u65b9\u5f0f\u5bf9\u5206\u533a\u7d22\u5f15\u8fdb\u884c\u7d22\u5f15\u8303\u56f4\u626b\u63cf\u800c\u4f7f\u7528\u8be5\u63d0\u793a\uff0c\u5e76\u4e14\u53ef\u4ee5\u6307\u5b9a\u8fdb\u7a0b\u7684\u4e2a\u6570\u3002<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">10. \u5176\u4ed6\u76f8\u5173\u7684<\/h2>\n\n\n\n<ul class=\"wp-block-list\">\n<li>APPEND<\/li>\n<\/ul>\n\n\n\n<p>\u8ba9\u6570\u636e\u5e93\u4ee5\u76f4\u63a5\u52a0\u8f7d\u7684\u65b9\u5f0f(direct load)\u5c06\u6570\u636e\u52a0\u8f7d\u5165\u5e93\u3002\u8fd9\u4e2a\u63d0\u793a\u4e0d\u4f1a\u68c0\u67e5\u5f53\u524d\u662f\u5426\u6709\u63d2\u5165\u6240\u9700\u8981\u7684\u5757\u7a7a\u95f4\uff0c\u76f8\u53cd\u5b83\u4f1a\u76f4\u63a5\u5c06\u6570\u636e\u6dfb\u52a0\u5230\u65b0\u5757\u4e2d\u3002\u8fd9\u6837\u4f1a\u6d6a\u8d39\u7a7a\u95f4\uff0c\u4f46\u53ef\u4ee5\u63d0\u9ad8\u63d2\u5165\u7684\u6027\u80fd\u3002\u9700\u8981\u6ce8\u610f\u7684\u662f\uff0c\u6570\u636e\u5c06\u88ab\u5b58\u50a8\u5728HWM\u4e4b\u4e0a\u7684\u4f4d\u7f6e\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>APPEND_VALUES<\/li>\n<\/ul>\n\n\n\n<p>\u572811.2\u4e2d\uff0cOracle\u65b0\u589e\u4e86APPEND_VALUES\u63d0\u793a\uff0c\u4f7f\u5f97INSERT INTO VALUES\u8bed\u53e5\u4e5f\u53ef\u4ee5\u4f7f\u7528\u76f4\u63a5\u8def\u5f84\u63d2\u5165\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>CACHE<\/li>\n<\/ul>\n\n\n\n<p>\u5728\u5168\u8868\u626b\u63cf\u4e4b\u540e\uff0c\u6570\u636e\u5757\u5c06\u7559\u5728LRU\u5217\u8868\u7684\u6700\u6d3b\u8dc3\u7aef\u3002\u5982\u679c\u8bbe\u7f6e\u8868\u7684CACHE\u5c5e\u6027\uff0c\u5b83\u7684\u4f5c\u7528\u548cHINT\u4e00\u6837\u3002\u8fd9\u4e2a\u63d0\u793a\u4f1a\u5c06\u5168\u8868\u626b\u63cf\u5168\u90e8\u7f13\u5b58\u5230\u5185\u5b58\u4e2d\u3002\u5982\u679c\u8868\u5f88\u5927\uff0c\u4f1a\u5360\u7528\u5927\u91cf\u5185\u5b58\u3002\u56e0\u6b64\u9002\u7528\u4e8e\u7528\u6237\u7ecf\u5e38\u8bbf\u95ee\u7684\u8f83\u5c0f\u7684\u8868\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>NOCACHE<\/li>\n<\/ul>\n\n\n\n<p>\u5f15\u5bfc\u4f18\u5316\u5668\u5c06\u901a\u8fc7\u5168\u8868\u626b\u63cf\u65b9\u5f0f\u83b7\u53d6\u7684\u6570\u636e\u5757\u7f13\u5b58\u5728LRU\u5217\u8868\u7684\u6700\u540e\u4f4d\u7f6e\uff0c\u8fd9\u6837\u53ef\u4ee5\u8ba9\u6570\u636e\u5e93\u5b9e\u4f8b\u7f13\u5b58\u4e2d\u7684\u8fd9\u4e9b\u6570\u636e\u5757\u88ab\u4f18\u5148\u6e05\u9664\u3002\u8fd9\u662f\u4f18\u5316\u5668\u5728Buffer Cache\u4e2d\u7ba1\u7406\u6570\u636e\u5757\u7684\u9ed8\u8ba4\u65b9\u6cd5(\u4ec5\u9488\u5bf9\u5168\u8868\u626b\u63cf)\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>QB_NAME<\/li>\n<\/ul>\n\n\n\n<p>\u4f7f\u7528\u8be5\u63d0\u793a\u4e3a\u67e5\u8be2\u8bed\u53e5\u5757\u547d\u540d\uff0c\u5728\u5176\u4ed6\u67e5\u8be2\u8bed\u53e5\u5757\u53ef\u4ee5\u76f4\u63a5\u4f7f\u7528\u8be5\u67e5\u8be2\u8bed\u53e5\u5757\u7684\u540d\u79f0\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>DRIVING_SITE<\/li>\n<\/ul>\n\n\n\n<p>\u8fd9\u4e2a\u63d0\u793a\u5728\u5206\u5e03\u5f0f\u6570\u636e\u5e93\u64cd\u4f5c\u4e2d\u6709\u7528\u3002\u6307\u5b9a\u8868\u662f\u5904\u7406\u8fde\u63a5\u6240\u5728\u7684\u4f4d\u7f6e\u3002\u53ef\u4ee5\u9650\u5236\u901a\u8fc7\u7f51\u7edc\u5904\u7406\u7684\u4fe1\u606f\u91cf\u3002\u6b64\u5916\uff0c\u8fd8\u53ef\u4ee5\u5efa\u7acb\u8fdc\u7a0b\u8868\u7684\u672c\u5730\u89c6\u56fe\u6765\u9650\u5236\u4ece\u8fdc\u7a0b\u7ad9\u70b9\u68c0\u7d22\u7684\u884c\u3002\u672c\u5730\u89c6\u56fe\u5e94\u8be5\u6709where\u5b50\u53e5\uff0c\u4ece\u800c\u89c6\u56fe\u53ef\u4ee5\u5728\u5c06\u884c\u53d1\u9001\u56de\u672c\u5730\u6570\u636e\u5e93\u4e4b\u524d\u9650\u5236\u4ece\u8fdc\u7a0b\u6570\u636e\u5e93\u8fd4\u56de\u7684\u884c\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>DYNAMIC_SAMPLING<\/li>\n<\/ul>\n\n\n\n<p>\u63d0\u793aSQL\u6267\u884c\u65f6\u52a8\u6001\u91c7\u6837\u7684\u7ea7\u522b\u3002\u8fd9\u4e2a\u7ea7\u522b\u4e3a0~10\uff0c\u5b83\u5c06\u8986\u76d6\u7cfb\u7edf\u9ed8\u8ba4\u7684\u52a8\u6001\u91c7\u6837\u7ea7\u522b\u3002\u7b49\u7ea7\u8d8a\u9ad8\uff0c\u6240\u83b7\u5f97\u7edf\u8ba1\u4fe1\u606f\u7684\u51c6\u786e\u7387\u8d8a\u9ad8\u3002\u8be5\u63d0\u793a\u7684\u529f\u80fd\u5c31\u662f\u4e3a\u4e86\u786e\u4fdd\u5c06\u52a8\u6001\u91c7\u6837\u539f\u7406\u5e94\u7528\u5728\u5355\u4e2aSQL\u4e2d\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>AND_EQUAL<\/li>\n<\/ul>\n\n\n\n<p>\u8fd9\u4e2a\u63d0\u793a\u4f1a\u4f7f\u4f18\u5316\u5668\u5408\u5e76\u8868\u4e0a\u7684\u591a\u4e2a\u7d22\u5f15\uff0c\u800c\u4e0d\u662f\u9009\u62e9\u5176\u4e2d\u6700\u597d\u7684\u7d22\u5f15(\u8fd9\u662fINDEX\u63d0\u793a\u7684\u7528\u9014)\u3002\u8fd9\u4e2a\u63d0\u793a\u4e0e\u524d\u9762\u7684INDEX_JOIN\u63d0\u793a\u6709\u533a\u522b\uff0c\u4ee5\u6b64\u6307\u5b9a\u7684\u5408\u5e76\u7d22\u5f15\u968f\u540e\u9700\u8bbf\u95ee\u8868\uff0c\u800cINDEX_JOIN\u63d0\u793a\u5219\u53ea\u9700\u8bbf\u95ee\u7d22\u5f15\u3002\u5982\u679c\u53d1\u73b0\u9700\u7ecf\u5e38\u7528\u5230\u8fd9\u4e2a\u63d0\u793a\uff0c\u53ef\u80fd\u9700\u8981\u5220\u9664\u8fd9\u4e9b\u5355\u4e2a\u7d22\u5f15\u800c\u6539\u7528\u4e00\u4e2a\u7ec4\u5408\u7d22\u5f15\u3002\u9700\u8981\u67e5\u8be2\u6761\u4ef6\u91cc\u9762\u5305\u62ec\u6240\u6709\u7d22\u5f15\u5217\uff0c\u7136\u540e\u53d6\u5f97\u6bcf\u4e2a\u7d22\u5f15\u4e2d\u5f97\u5230\u7684rowid\u5217\u8868\u3002\u7136\u540e\u5bf9\u8fd9\u4e9b\u5bf9\u8c61\u505amerge join\uff0c\u8fc7\u6ee4\u51fa\u76f8\u540c\u7684rowid\u540e\u518d\u53bb\u8868\u4e2d\u83b7\u53d6\u6570\u636e\u6216\u8005\u76f4\u63a5\u4ece\u7d22\u5f15\u4e2d\u83b7\u5f97\u6570\u636e\u3002\u572810g\u4e2d\uff0cand_equal\u5df2\u7ecf\u5e9f\u5f03\u4e86\uff0c\u53ea\u80fd\u901a\u8fc7hint\u624d\u80fd\u751f\u6548\u3002<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>CARDINALITY<\/li>\n<\/ul>\n\n\n\n<p>\u5411\u4f18\u5316\u5668\u63d0\u4f9b\u5bf9\u67d0\u4e2a\u67e5\u8be2\u8bed\u53e5\u7684\u6574\u4f53\u6216\u90e8\u5206\u7684\u9884\u6d4b\u57fa\u6570\u503c\uff0c\u5e76\u901a\u8fc7\u53c2\u8003\u8be5\u57fa\u6570\u503c\u6765\u4e3a\u67e5\u8be2\u8bed\u53e5\u5236\u5b9a\u6267\u884c\u8ba1\u5212\u3002\u5982\u679c\u5728\u8be5\u63d0\u793a\u4e2d\u6ca1\u6709\u6307\u5b9a\u8868\u7684\u540d\u79f0\uff0c\u5219\u8be5\u57fa\u6570\u503c\u5c06\u88ab\u89c6\u4e3a\u4ece\u8be5\u67e5\u8be2\u8bed\u53e5\u6240\u83b7\u5f97\u7684\u6700\u7ec8\u7ed3\u679c\u884c\u6570\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>1. Hint\uff08\u63d0\u793a\uff09\u7b80\u4ecb Hint\u662fOracle\u4e3a\u4e86\u4e0d\u7834\u574f\u548c\u5176\u4ed6\u6570\u636e\u5e93\u5f15\u64ce\u4e4b\u95f4\u5bf9SQL\u8bed\u53e5\u7684\u517c\u5bb9\u6027\u800c\u63d0\u4f9b\u7684\u4e00 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[199],"tags":[196],"class_list":["post-5118","post","type-post","status-publish","format-standard","hentry","category-oracle-","tag-oracle"],"_links":{"self":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/5118"}],"collection":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5118"}],"version-history":[{"count":3,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/5118\/revisions"}],"predecessor-version":[{"id":5121,"href":"https:\/\/qaqaq.top\/index.php?rest_route=\/wp\/v2\/posts\/5118\/revisions\/5121"}],"wp:attachment":[{"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5118"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5118"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qaqaq.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5118"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}