{"id":190696,"date":"2024-11-12T14:44:19","date_gmt":"2024-11-12T06:44:19","guid":{"rendered":"https:\/\/server.hk\/cnblog\/190696\/"},"modified":"2024-11-12T14:44:20","modified_gmt":"2024-11-12T06:44:20","slug":"%e4%ba%94%e5%88%86%e9%90%98%e7%b2%be%e9%80%9aoracle-hints","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/190696\/","title":{"rendered":"\u4e94\u5206\u9418\u7cbe\u901aOracle Hints"},"content":{"rendered":"<h1 id=\"%e4%ba%94%e5%88%86%e9%90%98%e7%b2%be%e9%80%9aoracle-hints-JmTQOtGlzu\">\u4e94\u5206\u9418\u7cbe\u901aOracle Hints<\/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\u8b93\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u80fd\u5920\u5f71\u97ff\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eOracle Hints\u7684\u57fa\u672c\u6982\u5ff5\u3001\u4f7f\u7528\u65b9\u6cd5\u53ca\u5176\u5728\u6027\u80fd\u512a\u5316\u4e2d\u7684\u61c9\u7528\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%aforacle-hints%ef%bc%9f-JmTQOtGlzu\">\u4ec0\u9ebc\u662fOracle Hints\uff1f<\/h2>\n<p>Oracle Hints\u662f\u7528\u4f86\u6307\u793aOracle\u67e5\u8a62\u512a\u5316\u5668\u5982\u4f55\u57f7\u884cSQL\u67e5\u8a62\u7684\u63d0\u793a\u3002\u9019\u4e9b\u63d0\u793a\u53ef\u4ee5\u544a\u8a34\u512a\u5316\u5668\u4f7f\u7528\u7279\u5b9a\u7684\u57f7\u884c\u8a08\u5283\u6216\u65b9\u6cd5\uff0c\u5f9e\u800c\u5f71\u97ff\u67e5\u8a62\u7684\u6027\u80fd\u3002Hints\u901a\u5e38\u4ee5\u8a3b\u89e3\u7684\u5f62\u5f0f\u5d4c\u5165\u5728SQL\u8a9e\u53e5\u4e2d\uff0c\u4e26\u4e14\u4e0d\u6703\u6539\u8b8a\u67e5\u8a62\u7684\u7d50\u679c\u3002<\/p>\n<h2 id=\"%e7%82%ba%e4%bb%80%e9%ba%bc%e4%bd%bf%e7%94%a8hints%ef%bc%9f-JmTQOtGlzu\">\u70ba\u4ec0\u9ebc\u4f7f\u7528Hints\uff1f<\/h2>\n<p>\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0cOracle\u7684\u81ea\u52d5\u512a\u5316\u5668\u53ef\u80fd\u7121\u6cd5\u9078\u64c7\u6700\u4f73\u7684\u57f7\u884c\u8a08\u5283\u3002\u9019\u53ef\u80fd\u662f\u7531\u65bc\u7d71\u8a08\u4fe1\u606f\u4e0d\u6e96\u78ba\u3001\u6578\u64da\u5206\u4f48\u4e0d\u5747\u6216\u67e5\u8a62\u7684\u8907\u96dc\u6027\u7b49\u539f\u56e0\u3002\u4f7f\u7528Hints\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u5728\u9019\u4e9b\u60c5\u6cc1\u4e0b\u624b\u52d5\u8abf\u6574\u67e5\u8a62\u7684\u57f7\u884c\u65b9\u5f0f\uff0c\u4ee5\u63d0\u9ad8\u6027\u80fd\u3002<\/p>\n<h2 id=\"%e5%b8%b8%e8%a6%8b%e7%9a%84oracle-hints-JmTQOtGlzu\">\u5e38\u898b\u7684Oracle Hints<\/h2>\n<p>\u4ee5\u4e0b\u662f\u4e00\u4e9b\u5e38\u7528\u7684Oracle Hints\uff1a<\/p>\n<ul>\n<li><code>ALL_ROWS<\/code>\uff1a\u544a\u8a34\u512a\u5316\u5668\u9078\u64c7\u4e00\u500b\u80fd\u5920\u8fd4\u56de\u6240\u6709\u884c\u7684\u6700\u4f73\u57f7\u884c\u8a08\u5283\uff0c\u9069\u5408\u9700\u8981\u8655\u7406\u5927\u91cf\u6578\u64da\u7684\u67e5\u8a62\u3002<\/li>\n<li><code>FIRST_ROWS(n)<\/code>\uff1a\u6307\u793a\u512a\u5316\u5668\u512a\u5148\u8fd4\u56de\u524dn\u884c\uff0c\u9069\u5408\u9700\u8981\u5feb\u901f\u97ff\u61c9\u7684\u67e5\u8a62\u3002<\/li>\n<li><code>USE_NL<\/code>\uff1a\u5f37\u5236\u4f7f\u7528\u5d4c\u5957\u5faa\u74b0\u9023\u63a5\uff0c\u9069\u5408\u5c0f\u6578\u64da\u96c6\u7684\u9023\u63a5\u67e5\u8a62\u3002<\/li>\n<li><code>USE_HASH<\/code>\uff1a\u5f37\u5236\u4f7f\u7528\u54c8\u5e0c\u9023\u63a5\uff0c\u9069\u5408\u5927\u6578\u64da\u96c6\u7684\u9023\u63a5\u67e5\u8a62\u3002<\/li>\n<li><code>LEADING<\/code>\uff1a\u6307\u5b9a\u67e5\u8a62\u4e2d\u8868\u7684\u806f\u63a5\u9806\u5e8f\uff0c\u9019\u5c0d\u65bc\u8907\u96dc\u7684\u67e5\u8a62\u7279\u5225\u6709\u7528\u3002<\/li>\n<\/ul>\n<h2 id=\"%e5%a6%82%e4%bd%95%e4%bd%bf%e7%94%a8oracle-hints-JmTQOtGlzu\">\u5982\u4f55\u4f7f\u7528Oracle Hints<\/h2>\n<p>\u4f7f\u7528Hints\u975e\u5e38\u7c21\u55ae\uff0c\u53ea\u9700\u5c07\u5176\u6dfb\u52a0\u5230SQL\u67e5\u8a62\u4e2d\u5373\u53ef\u3002\u4ee5\u4e0b\u662f\u4e00\u500b\u793a\u4f8b\uff1a<\/p>\n<pre><code>\nSELECT \/*+ USE_NL(t1 t2) *\/ *\nFROM table1 t1, table2 t2\nWHERE t1.id = t2.id;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c<code>USE_NL<\/code>\u63d0\u793a\u544a\u8a34\u512a\u5316\u5668\u4f7f\u7528\u5d4c\u5957\u5faa\u74b0\u9023\u63a5\u4f86\u57f7\u884c\u67e5\u8a62\u3002<\/p>\n<h2 id=\"%e6%b3%a8%e6%84%8f%e4%ba%8b%e9%a0%85-JmTQOtGlzu\">\u6ce8\u610f\u4e8b\u9805<\/h2>\n<p>\u96d6\u7136Hints\u53ef\u4ee5\u5e6b\u52a9\u512a\u5316\u67e5\u8a62\u6027\u80fd\uff0c\u4f46\u904e\u5ea6\u4f9d\u8cf4Hints\u53ef\u80fd\u6703\u5c0e\u81f4\u67e5\u8a62\u7684\u53ef\u7dad\u8b77\u6027\u964d\u4f4e\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b\u4f7f\u7528Hints\u6642\u7684\u6ce8\u610f\u4e8b\u9805\uff1a<\/p>\n<ul>\n<li>\u5728\u4f7f\u7528Hints\u4e4b\u524d\uff0c\u61c9\u8a72\u5148\u5206\u6790\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\uff0c\u78ba\u5b9a\u662f\u5426\u771f\u7684\u9700\u8981\u4f7f\u7528Hints\u3002<\/li>\n<li>\u5b9a\u671f\u6aa2\u67e5\u548c\u66f4\u65b0\u7d71\u8a08\u4fe1\u606f\uff0c\u4ee5\u78ba\u4fdd\u512a\u5316\u5668\u80fd\u5920\u505a\u51fa\u6b63\u78ba\u7684\u6c7a\u7b56\u3002<\/li>\n<li>\u5728\u4e0d\u540c\u7684\u6578\u64da\u74b0\u5883\u4e2d\uff0cHints\u7684\u6548\u679c\u53ef\u80fd\u6703\u6709\u6240\u4e0d\u540c\uff0c\u56e0\u6b64\u9700\u8981\u9032\u884c\u6e2c\u8a66\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-JmTQOtGlzu\">\u7e3d\u7d50<\/h2>\n<p>Oracle Hints\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u5de5\u5177\uff0c\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u548c\u6578\u64da\u5eab\u7ba1\u7406\u54e1\u512a\u5316\u67e5\u8a62\u6027\u80fd\u3002\u901a\u904e\u5408\u7406\u4f7f\u7528Hints\uff0c\u53ef\u4ee5\u5728\u7279\u5b9a\u60c5\u6cc1\u4e0b\u986f\u8457\u63d0\u9ad8\u67e5\u8a62\u7684\u57f7\u884c\u6548\u7387\u3002\u7136\u800c\uff0c\u4f7f\u7528Hints\u6642\u9700\u8b39\u614e\uff0c\u4ee5\u514d\u5f71\u97ff\u67e5\u8a62\u7684\u53ef\u7dad\u8b77\u6027\u548c\u7a69\u5b9a\u6027\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u6548\u80fd\u7684\u61c9\u7528\uff0c\u9078\u64c7\u5408\u9069\u7684<a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a>\u6216<a href=\"https:\/\/server.hk\">\u4e91\u4f3a\u670d\u5668<\/a>\u89e3\u6c7a\u65b9\u6848\u4e5f\u662f\u81f3\u95dc\u91cd\u8981\u7684\uff0c\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u6578\u64da\u5eab\u7684\u7a69\u5b9a\u904b\u884c\u548c\u5feb\u901f\u97ff\u61c9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u638c\u63e1Oracle Hints\u7684\u6280\u5de7\uff0c\u4e94\u5206\u9418\u5167\u63d0\u5347\u67e5\u8a62\u6027\u80fd\uff0c\u512a\u5316\u6578\u64da\u5eab\u64cd\u4f5c\uff0c\u8b93\u4f60\u7684SQL\u8a9e\u53e5\u66f4\u9ad8\u6548\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-190696","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/190696","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=190696"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/190696\/revisions"}],"predecessor-version":[{"id":190697,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/190696\/revisions\/190697"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=190696"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=190696"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=190696"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}