{"id":95370,"date":"2024-10-20T00:29:19","date_gmt":"2024-10-19T16:29:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/95370\/"},"modified":"2024-10-20T00:29:20","modified_gmt":"2024-10-19T16:29:20","slug":"oracle%e4%bd%bf%e7%94%a8hints%e7%9a%84%e8%aa%bf%e6%95%b4%e6%a9%9f%e5%88%b6%e8%a7%a3%e6%9e%90%e4%bb%8b%e7%b4%b9","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/95370\/","title":{"rendered":"Oracle\u4f7f\u7528hints\u7684\u8abf\u6574\u6a5f\u5236\u89e3\u6790\u4ecb\u7d39"},"content":{"rendered":"<h1 id=\"oracle%e4%bd%bf%e7%94%a8hints%e7%9a%84%e8%aa%bf%e6%95%b4%e6%a9%9f%e5%88%b6%e8%a7%a3%e6%9e%90%e4%bb%8b%e7%b4%b9-HiKLHaQoFX\">Oracle\u4f7f\u7528hints\u7684\u8abf\u6574\u6a5f\u5236\u89e3\u6790\u4ecb\u7d39<\/h1>\n<p>\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\uff0c\u6027\u80fd\u512a\u5316\u662f\u4e00\u500b\u81f3\u95dc\u91cd\u8981\u7684\u8ab2\u984c\u3002Oracle\u6578\u64da\u5eab\u63d0\u4f9b\u4e86\u4e00\u7a2e\u540d\u70ba\u300chints\u300d\u7684\u529f\u80fd\uff0c\u5141\u8a31\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u5728\u67e5\u8a62\u4e2d\u63d0\u4f9b\u6307\u5c0e\uff0c\u4ee5\u5f71\u97ff\u67e5\u8a62\u512a\u5316\u5668\u7684\u884c\u70ba\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eOracle\u4f7f\u7528hints\u7684\u8abf\u6574\u6a5f\u5236\uff0c\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3\u5176\u904b\u4f5c\u539f\u7406\u53ca\u61c9\u7528\u5834\u666f\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%afhints%ef%bc%9f-HiKLHaQoFX\">\u4ec0\u9ebc\u662fHints\uff1f<\/h2>\n<p>Hints\u662fOracle\u6578\u64da\u5eab\u4e2d\u7528\u4f86\u6307\u793a\u67e5\u8a62\u512a\u5316\u5668\u5982\u4f55\u57f7\u884cSQL\u8a9e\u53e5\u7684\u63d0\u793a\u3002\u9019\u4e9b\u63d0\u793a\u4e0d\u6703\u6539\u8b8aSQL\u8a9e\u53e5\u7684\u8a9e\u6cd5\uff0c\u4f46\u6703\u5f71\u97ff\u512a\u5316\u5668\u9078\u64c7\u7684\u57f7\u884c\u8a08\u5283\u3002\u4f7f\u7528hints\u53ef\u4ee5\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u7279\u5225\u662f\u5728\u512a\u5316\u5668\u7121\u6cd5\u81ea\u52d5\u9078\u64c7\u6700\u4f73\u8a08\u5283\u7684\u60c5\u6cc1\u4e0b\u3002<\/p>\n<h2 id=\"hints%e7%9a%84%e9%a1%9e%e5%9e%8b-HiKLHaQoFX\">Hints\u7684\u985e\u578b<\/h2>\n<p>Oracle\u63d0\u4f9b\u4e86\u591a\u7a2e\u4e0d\u540c\u985e\u578b\u7684hints\uff0c\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u898b\u7684\u985e\u578b\uff1a<\/p>\n<ul>\n<li><strong>\u5168\u5c40\u63d0\u793a\uff08Global Hints\uff09<\/strong>: \u9019\u4e9b\u63d0\u793a\u5f71\u97ff\u6574\u500b\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u4f8b\u5982\u4f7f\u7528<code>ALL_ROWS<\/code>\u63d0\u793a\u4f86\u512a\u5316\u6574\u9ad4\u67e5\u8a62\u6027\u80fd\u3002<\/li>\n<li><strong>\u8868\u63d0\u793a\uff08Table Hints\uff09<\/strong>: \u9019\u4e9b\u63d0\u793a\u91dd\u5c0d\u7279\u5b9a\u7684\u8868\uff0c\u4f8b\u5982\u4f7f\u7528<code>USE_NL<\/code>\u63d0\u793a\u4f86\u5f37\u5236\u4f7f\u7528\u5d4c\u5957\u5faa\u74b0\u9023\u63a5\u3002<\/li>\n<li><strong>\u7d22\u5f15\u63d0\u793a\uff08Index Hints\uff09<\/strong>: \u9019\u4e9b\u63d0\u793a\u7528\u65bc\u6307\u5b9a\u4f7f\u7528\u7279\u5b9a\u7684\u7d22\u5f15\uff0c\u4f8b\u5982<code>INDEX(table_name index_name)<\/code>\u3002<\/li>\n<li><strong>\u9023\u63a5\u63d0\u793a\uff08Join Hints\uff09<\/strong>: \u9019\u4e9b\u63d0\u793a\u7528\u65bc\u63a7\u5236\u8868\u4e4b\u9593\u7684\u9023\u63a5\u65b9\u5f0f\uff0c\u4f8b\u5982<code>LEADING<\/code>\u63d0\u793a\u4f86\u6307\u5b9a\u9023\u63a5\u7684\u9806\u5e8f\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8hints-HiKLHaQoFX\">\u5982\u4f55\u4f7f\u7528Hints<\/h2>\n<p>\u4f7f\u7528hints\u7684\u57fa\u672c\u8a9e\u6cd5\u5982\u4e0b\uff1a<\/p>\n<pre><code>SELECT \/*+ hint_name *\/ column1, column2\nFROM table_name\nWHERE condition;<\/code><\/pre>\n<p>\u4f8b\u5982\uff0c\u82e5\u8981\u5f37\u5236\u4f7f\u7528\u7279\u5b9a\u7684\u7d22\u5f15\uff0c\u53ef\u4ee5\u9019\u6a23\u5beb\uff1a<\/p>\n<pre><code>SELECT \/*+ INDEX(emp emp_idx) *\/ *\nFROM employees emp\nWHERE emp.department_id = 10;<\/code><\/pre>\n<h2 id=\"hints%e7%9a%84%e5%84%aa%e7%bc%ba%e9%bb%9e-HiKLHaQoFX\">Hints\u7684\u512a\u7f3a\u9ede<\/h2>\n<p>\u4f7f\u7528hints\u6709\u5176\u512a\u7f3a\u9ede\uff0c\u4ee5\u4e0b\u662f\u4e00\u4e9b\u8003\u91cf\u56e0\u7d20\uff1a<\/p>\n<h3 id=\"%e5%84%aa%e9%bb%9e-HiKLHaQoFX\">\u512a\u9ede<\/h3>\n<ul>\n<li><strong>\u6027\u80fd\u63d0\u5347<\/strong>: \u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u4f7f\u7528hints\u53ef\u4ee5\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u6027\u80fd\uff0c\u7279\u5225\u662f\u7576\u512a\u5316\u5668\u7121\u6cd5\u81ea\u52d5\u9078\u64c7\u6700\u4f73\u8a08\u5283\u6642\u3002<\/li>\n<li><strong>\u63a7\u5236\u57f7\u884c\u8a08\u5283<\/strong>: \u958b\u767c\u8005\u53ef\u4ee5\u66f4\u7cbe\u78ba\u5730\u63a7\u5236\u67e5\u8a62\u7684\u57f7\u884c\u65b9\u5f0f\uff0c\u5f9e\u800c\u9054\u5230\u9810\u671f\u7684\u6027\u80fd\u76ee\u6a19\u3002<\/li>\n<\/ul>\n<h3 id=\"%e7%bc%ba%e9%bb%9e-HiKLHaQoFX\">\u7f3a\u9ede<\/h3>\n<ul>\n<li><strong>\u7dad\u8b77\u6210\u672c<\/strong>: \u4f7f\u7528hints\u53ef\u80fd\u6703\u589e\u52a0SQL\u8a9e\u53e5\u7684\u8907\u96dc\u6027\uff0c\u4e26\u5728\u6578\u64da\u5eab\u7d50\u69cb\u8b8a\u66f4\u6642\u9700\u8981\u9032\u884c\u8abf\u6574\u3002<\/li>\n<li><strong>\u4f9d\u8cf4\u6027<\/strong>: \u904e\u5ea6\u4f9d\u8cf4hints\u53ef\u80fd\u6703\u5c0e\u81f4\u67e5\u8a62\u6027\u80fd\u4e0d\u7a69\u5b9a\uff0c\u56e0\u70ba\u96a8\u8457\u6578\u64da\u91cf\u7684\u8b8a\u5316\uff0c\u6700\u4f73\u57f7\u884c\u8a08\u5283\u4e5f\u53ef\u80fd\u96a8\u4e4b\u6539\u8b8a\u3002<\/li>\n<\/ul>\n<h2 id=\"%e6%9c%80%e4%bd%b3%e5%af%a6%e8%b8%90-HiKLHaQoFX\">\u6700\u4f73\u5be6\u8e10<\/h2>\n<p>\u5728\u4f7f\u7528hints\u6642\uff0c\u5efa\u8b70\u9075\u5faa\u4ee5\u4e0b\u6700\u4f73\u5be6\u8e10\uff1a<\/p>\n<ul>\n<li>\u5728\u6027\u80fd\u6e2c\u8a66\u4e2d\u8a55\u4f30hints\u7684\u5f71\u97ff\uff0c\u78ba\u4fdd\u5176\u5be6\u969b\u63d0\u5347\u4e86\u67e5\u8a62\u6027\u80fd\u3002<\/li>\n<li>\u5b9a\u671f\u6aa2\u67e5\u548c\u66f4\u65b0\u4f7f\u7528\u7684hints\uff0c\u4ee5\u9069\u61c9\u6578\u64da\u5eab\u7d50\u69cb\u548c\u6578\u64da\u91cf\u7684\u8b8a\u5316\u3002<\/li>\n<li>\u907f\u514d\u904e\u5ea6\u4f7f\u7528hints\uff0c\u61c9\u9996\u5148\u5617\u8a66\u901a\u904e\u5176\u4ed6\u512a\u5316\u624b\u6bb5\u4f86\u6539\u5584\u6027\u80fd\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-HiKLHaQoFX\">\u7e3d\u7d50<\/h2>\n<p>Oracle\u7684hints\u529f\u80fd\u70ba\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u63d0\u4f9b\u4e86\u4e00\u7a2e\u9748\u6d3b\u7684\u65b9\u5f0f\u4f86\u512a\u5316\u67e5\u8a62\u6027\u80fd\u3002\u96d6\u7136\u4f7f\u7528hints\u53ef\u4ee5\u5728\u7279\u5b9a\u60c5\u6cc1\u4e0b\u986f\u8457\u63d0\u9ad8\u6027\u80fd\uff0c\u4f46\u4e5f\u9700\u8981\u8b39\u614e\u4f7f\u7528\uff0c\u4ee5\u907f\u514d\u672a\u4f86\u7684\u7dad\u8b77\u554f\u984c\u3002\u4e86\u89e3hints\u7684\u985e\u578b\u53ca\u5176\u4f7f\u7528\u65b9\u6cd5\uff0c\u4e26\u9075\u5faa\u6700\u4f73\u5be6\u8e10\uff0c\u5c07\u6709\u52a9\u65bc\u5728\u6578\u64da\u5eab\u7ba1\u7406\u4e2d\u53d6\u5f97\u66f4\u597d\u7684\u6548\u679c\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u6709\u95dc<code><a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a><\/code>\u548c<code><a href=\"https:\/\/server.hk\">\u4e91\u670d\u52a1\u5668<\/a><\/code>\u7684\u8cc7\u8a0a\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6df1\u5165\u89e3\u6790Oracle\u4f7f\u7528hints\u7684\u8abf\u6574\u6a5f\u5236\uff0c\u63a2\u8a0e\u5176\u5c0d\u67e5\u8a62\u6027\u80fd\u512a\u5316\u7684\u5f71\u97ff\u8207\u61c9\u7528\u6280\u5de7\u3002<\/p>\n","protected":false},"author":0,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-95370","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95370","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/types\/post"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=95370"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95370\/revisions"}],"predecessor-version":[{"id":95371,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/95370\/revisions\/95371"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=95370"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=95370"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=95370"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}