{"id":60505,"date":"2024-10-13T03:25:15","date_gmt":"2024-10-12T19:25:15","guid":{"rendered":"https:\/\/server.hk\/cnblog\/60505\/"},"modified":"2024-10-13T03:25:15","modified_gmt":"2024-10-12T19:25:15","slug":"db2%e9%9a%94%e9%9b%a2%e7%b4%9a%e7%9a%84%e6%ad%a3%e7%a2%ba%e8%a7%a3%e8%ae%80%e5%92%8c%e8%a9%a6%e9%a9%97%e7%9a%84%e6%8f%8f%e8%bf%b0","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/60505\/","title":{"rendered":"DB2\u9694\u96e2\u7d1a\u7684\u6b63\u78ba\u89e3\u8b80\u548c\u8a66\u9a57\u7684\u63cf\u8ff0"},"content":{"rendered":"<h1 id=\"db2%e9%9a%94%e9%9b%a2%e7%b4%9a%e7%9a%84%e6%ad%a3%e7%a2%ba%e8%a7%a3%e8%ae%80%e5%92%8c%e8%a9%a6%e9%a9%97%e7%9a%84%e6%8f%8f%e8%bf%b0-xlrNUfkrgl\">DB2\u9694\u96e2\u7d1a\u7684\u6b63\u78ba\u89e3\u8b80\u548c\u8a66\u9a57\u7684\u63cf\u8ff0<\/h1>\n<p>\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u9694\u96e2\u7d1a\u662f\u78ba\u4fdd\u8cc7\u6599\u4e00\u81f4\u6027\u548c\u5b8c\u6574\u6027\u7684\u91cd\u8981\u6982\u5ff5\u3002IBM\u7684DB2\u8cc7\u6599\u5eab\u7cfb\u7d71\u63d0\u4f9b\u4e86\u591a\u7a2e\u9694\u96e2\u7d1a\uff0c\u8b93\u4f7f\u7528\u8005\u53ef\u4ee5\u6839\u64da\u61c9\u7528\u9700\u6c42\u9078\u64c7\u5408\u9069\u7684\u8a2d\u5b9a\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eDB2\u7684\u9694\u96e2\u7d1a\uff0c\u4e26\u63d0\u4f9b\u76f8\u95dc\u7684\u8a66\u9a57\u63cf\u8ff0\uff0c\u4ee5\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3\u9019\u4e00\u4e3b\u984c\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af%e9%9a%94%e9%9b%a2%e7%b4%9a%ef%bc%9f-xlrNUfkrgl\">\u4ec0\u9ebc\u662f\u9694\u96e2\u7d1a\uff1f<\/h2>\n<p>\u9694\u96e2\u7d1a\u662f\u6307\u5728\u591a\u500b\u4ea4\u6613\u540c\u6642\u57f7\u884c\u6642\uff0c\u5982\u4f55\u63a7\u5236\u9019\u4e9b\u4ea4\u6613\u4e4b\u9593\u7684\u76f8\u4e92\u5f71\u97ff\u3002\u6839\u64daSQL\u6a19\u6e96\uff0c\u9694\u96e2\u7d1a\u4e3b\u8981\u5206\u70ba\u56db\u7a2e\uff1a<\/p>\n<ul>\n<li><strong>\u8b80\u672a\u63d0\u4ea4\uff08Read Uncommitted\uff09<\/strong><\/li>\n<li><strong>\u8b80\u5df2\u63d0\u4ea4\uff08Read Committed\uff09<\/strong><\/li>\n<li><strong>\u53ef\u91cd\u8907\u8b80\uff08Repeatable Read\uff09<\/strong><\/li>\n<li><strong>\u5e8f\u5217\u5316\uff08Serializable\uff09<\/strong><\/li>\n<\/ul>\n<h2 id=\"db2%e7%9a%84%e9%9a%94%e9%9b%a2%e7%b4%9a%e8%a9%b3%e8%a7%a3-xlrNUfkrgl\">DB2\u7684\u9694\u96e2\u7d1a\u8a73\u89e3<\/h2>\n<h3 id=\"1-%e8%ae%80%e6%9c%aa%e6%8f%90%e4%ba%a4%ef%bc%88read-uncommitted%ef%bc%89-xlrNUfkrgl\">1. \u8b80\u672a\u63d0\u4ea4\uff08Read Uncommitted\uff09<\/h3>\n<p>\u5728\u9019\u4e00\u9694\u96e2\u7d1a\u4e0b\uff0c\u4ea4\u6613\u53ef\u4ee5\u8b80\u53d6\u5176\u4ed6\u672a\u63d0\u4ea4\u4ea4\u6613\u7684\u8cc7\u6599\u3002\u9019\u610f\u5473\u8457\u53ef\u80fd\u6703\u51fa\u73fe\u300c\u9ad2\u8b80\u300d\u7684\u60c5\u6cc1\uff0c\u5373\u8b80\u53d6\u5230\u7684\u8cc7\u6599\u53ef\u80fd\u6703\u5728\u5f8c\u7e8c\u7684\u4ea4\u6613\u4e2d\u88ab\u56de\u6efe\u3002<\/p>\n<h3 id=\"2-%e8%ae%80%e5%b7%b2%e6%8f%90%e4%ba%a4%ef%bc%88read-committed%ef%bc%89-xlrNUfkrgl\">2. \u8b80\u5df2\u63d0\u4ea4\uff08Read Committed\uff09<\/h3>\n<p>\u6b64\u9694\u96e2\u7d1a\u78ba\u4fdd\u4ea4\u6613\u53ea\u80fd\u8b80\u53d6\u5df2\u63d0\u4ea4\u7684\u8cc7\u6599\u3002\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u9ad2\u8b80\uff0c\u4f46\u4ecd\u7136\u53ef\u80fd\u51fa\u73fe\u300c\u4e0d\u53ef\u91cd\u8907\u8b80\u300d\u7684\u60c5\u6cc1\uff0c\u5373\u5728\u540c\u4e00\u4ea4\u6613\u4e2d\u591a\u6b21\u8b80\u53d6\u76f8\u540c\u8cc7\u6599\u6642\uff0c\u53ef\u80fd\u6703\u5f97\u5230\u4e0d\u540c\u7684\u7d50\u679c\u3002<\/p>\n<h3 id=\"3-%e5%8f%af%e9%87%8d%e8%a4%87%e8%ae%80%ef%bc%88repeatable-read%ef%bc%89-xlrNUfkrgl\">3. \u53ef\u91cd\u8907\u8b80\uff08Repeatable Read\uff09<\/h3>\n<p>\u5728\u53ef\u91cd\u8907\u8b80\u9694\u96e2\u7d1a\u4e0b\uff0c\u4ea4\u6613\u5728\u57f7\u884c\u904e\u7a0b\u4e2d\uff0c\u5c0d\u65bc\u5df2\u8b80\u53d6\u7684\u8cc7\u6599\uff0c\u5176\u4ed6\u4ea4\u6613\u7121\u6cd5\u5c0d\u5176\u9032\u884c\u4fee\u6539\u3002\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u4e0d\u53ef\u91cd\u8907\u8b80\u7684\u60c5\u6cc1\uff0c\u4f46\u4ecd\u7136\u53ef\u80fd\u51fa\u73fe\u300c\u5e7b\u8b80\u300d\u7684\u554f\u984c\uff0c\u5373\u5728\u540c\u4e00\u4ea4\u6613\u4e2d\uff0c\u65b0\u589e\u7684\u8cc7\u6599\u53ef\u80fd\u6703\u5f71\u97ff\u67e5\u8a62\u7d50\u679c\u3002<\/p>\n<h3 id=\"4-%e5%ba%8f%e5%88%97%e5%8c%96%ef%bc%88serializable%ef%bc%89-xlrNUfkrgl\">4. \u5e8f\u5217\u5316\uff08Serializable\uff09<\/h3>\n<p>\u5e8f\u5217\u5316\u662f\u6700\u9ad8\u7684\u9694\u96e2\u7d1a\uff0c\u78ba\u4fdd\u4ea4\u6613\u4e4b\u9593\u5b8c\u5168\u9694\u96e2\u3002\u9019\u610f\u5473\u8457\u5728\u4e00\u500b\u4ea4\u6613\u57f7\u884c\u671f\u9593\uff0c\u5176\u4ed6\u4ea4\u6613\u7121\u6cd5\u8b80\u53d6\u6216\u4fee\u6539\u4efb\u4f55\u8cc7\u6599\u3002\u96d6\u7136\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u6240\u6709\u7684\u8b80\u53d6\u554f\u984c\uff0c\u4f46\u6703\u986f\u8457\u964d\u4f4e\u7cfb\u7d71\u7684\u4e26\u767c\u6027\u548c\u6027\u80fd\u3002<\/p>\n<h2 id=\"db2%e9%9a%94%e9%9b%a2%e7%b4%9a%e7%9a%84%e8%a9%a6%e9%a9%97%e6%8f%8f%e8%bf%b0-xlrNUfkrgl\">DB2\u9694\u96e2\u7d1a\u7684\u8a66\u9a57\u63cf\u8ff0<\/h2>\n<p>\u70ba\u4e86\u66f4\u597d\u5730\u7406\u89e3DB2\u7684\u9694\u96e2\u7d1a\uff0c\u6211\u5011\u53ef\u4ee5\u9032\u884c\u4e00\u4e9b\u7c21\u55ae\u7684\u8a66\u9a57\u3002\u4ee5\u4e0b\u662f\u4f7f\u7528SQL\u8a9e\u53e5\u9032\u884c\u7684\u793a\u7bc4\uff1a<\/p>\n<pre><code>-- \u8a2d\u5b9a\u9694\u96e2\u7d1a\u70ba\u8b80\u5df2\u63d0\u4ea4\nSET TRANSACTION ISOLATION LEVEL READ COMMITTED;\n\n-- \u958b\u59cb\u4ea4\u6613\nBEGIN;\n\n-- \u67e5\u8a62\u8cc7\u6599\nSELECT * FROM employees WHERE department = 'Sales';\n\n-- \u63d0\u4ea4\u4ea4\u6613\nCOMMIT;<\/code><\/pre>\n<p>\u5728\u9019\u500b\u4f8b\u5b50\u4e2d\uff0c\u6211\u5011\u8a2d\u5b9a\u4e86\u9694\u96e2\u7d1a\u70ba\u8b80\u5df2\u63d0\u4ea4\uff0c\u4e26\u67e5\u8a62\u4e86\u92b7\u552e\u90e8\u9580\u7684\u54e1\u5de5\u8cc7\u6599\u3002\u9019\u6a23\u53ef\u4ee5\u78ba\u4fdd\u6211\u5011\u8b80\u53d6\u5230\u7684\u8cc7\u6599\u662f\u5df2\u63d0\u4ea4\u7684\uff0c\u907f\u514d\u4e86\u9ad2\u8b80\u7684\u60c5\u6cc1\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-xlrNUfkrgl\">\u7d50\u8ad6<\/h2>\n<p>DB2\u7684\u9694\u96e2\u7d1a\u662f\u8cc7\u6599\u5eab\u7ba1\u7406\u4e2d\u4e00\u500b\u91cd\u8981\u7684\u6982\u5ff5\uff0c\u6b63\u78ba\u7684\u7406\u89e3\u548c\u61c9\u7528\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u8a2d\u8a08\u51fa\u66f4\u7a69\u5b9a\u548c\u9ad8\u6548\u7684\u7cfb\u7d71\u3002\u6839\u64da\u4e0d\u540c\u7684\u61c9\u7528\u9700\u6c42\uff0c\u9078\u64c7\u5408\u9069\u7684\u9694\u96e2\u7d1a\u662f\u81f3\u95dc\u91cd\u8981\u7684\u3002\u900f\u904e\u672c\u6587\u7684\u4ecb\u7d39\u548c\u8a66\u9a57\u793a\u7bc4\uff0c\u5e0c\u671b\u80fd\u5920\u5e6b\u52a9\u8b80\u8005\u66f4\u6df1\u5165\u5730\u7406\u89e3DB2\u7684\u9694\u96e2\u7d1a\u3002<\/p>\n<p>\u5982\u9700\u9032\u4e00\u6b65\u4e86\u89e3\u6709\u95dc<em><a href=\"https:\/\/server.hk\">\u9999\u6e2fVPS<\/a><\/em>\u548c<em><a href=\"https:\/\/server.hk\">\u4f3a\u670d\u5668<\/a><\/em>\u7684\u8cc7\u8a0a\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6df1\u5165\u63a2\u8a0eDB2\u9694\u96e2\u7d1a\u7684\u6b63\u78ba\u89e3\u8b80\u8207\u8a66\u9a57\u65b9\u6cd5\uff0c\u5e6b\u52a9\u958b\u767c\u8005\u512a\u5316\u6578\u64da\u4e00\u81f4\u6027\u8207\u6027\u80fd\u3002<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-60505","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60505","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"}],"author":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/comments?post=60505"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60505\/revisions"}],"predecessor-version":[{"id":60506,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/60505\/revisions\/60506"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=60505"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=60505"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=60505"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}