{"id":158763,"date":"2024-11-03T04:36:49","date_gmt":"2024-11-02T20:36:49","guid":{"rendered":"https:\/\/server.hk\/cnblog\/158763\/"},"modified":"2024-11-03T04:36:49","modified_gmt":"2024-11-02T20:36:49","slug":"%e9%97%9c%e6%96%bcdb2%e9%9a%94%e9%9b%a2%e7%b4%9a%e8%a7%a3%e8%ae%80%e5%92%8c%e8%a9%a6%e9%a9%97%e7%9a%84%e5%80%8b%e4%ba%ba%e8%b3%87%e6%96%99","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/158763\/","title":{"rendered":"\u95dc\u65bcDB2\u9694\u96e2\u7d1a\u89e3\u8b80\u548c\u8a66\u9a57\u7684\u500b\u4eba\u8cc7\u6599"},"content":{"rendered":"<h1 id=\"%e9%97%9c%e6%96%bcdb2%e9%9a%94%e9%9b%a2%e7%b4%9a%e8%a7%a3%e8%ae%80%e5%92%8c%e8%a9%a6%e9%a9%97%e7%9a%84%e5%80%8b%e4%ba%ba%e8%b3%87%e6%96%99-AIQtClVlyp\">\u95dc\u65bcDB2\u9694\u96e2\u7d1a\u89e3\u8b80\u548c\u8a66\u9a57\u7684\u500b\u4eba\u8cc7\u6599<\/h1>\n<p>\u5728\u8cc7\u6599\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0c\u9694\u96e2\u7d1a\u5225\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\u5225\uff0c\u9019\u4e9b\u7d1a\u5225\u6c7a\u5b9a\u4e86\u5728\u591a\u7528\u6236\u74b0\u5883\u4e2d\uff0c\u4e8b\u52d9\u4e4b\u9593\u5982\u4f55\u76f8\u4e92\u5f71\u97ff\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0eDB2\u7684\u9694\u96e2\u7d1a\u5225\uff0c\u4e26\u63d0\u4f9b\u4e00\u4e9b\u5be6\u9a57\u4f86\u5e6b\u52a9\u7406\u89e3\u9019\u4e9b\u6982\u5ff5\u3002<\/p>\n<h2 id=\"db2%e7%9a%84%e9%9a%94%e9%9b%a2%e7%b4%9a%e5%88%a5-AIQtClVlyp\">DB2\u7684\u9694\u96e2\u7d1a\u5225<\/h2>\n<p>DB2\u652f\u6301\u56db\u7a2e\u4e3b\u8981\u7684\u9694\u96e2\u7d1a\u5225\uff0c\u6bcf\u4e00\u7a2e\u90fd\u6709\u5176\u7279\u5b9a\u7684\u7279\u6027\u548c\u9069\u7528\u5834\u666f\uff1a<\/p>\n<ul>\n<li><strong>\u8b80\u53d6\u672a\u63d0\u4ea4\uff08Read Uncommitted\uff09<\/strong>: \u9019\u662f\u6700\u4f4e\u7684\u9694\u96e2\u7d1a\u5225\uff0c\u5141\u8a31\u4e8b\u52d9\u8b80\u53d6\u5176\u4ed6\u4e8b\u52d9\u5c1a\u672a\u63d0\u4ea4\u7684\u8b8a\u66f4\u3002\u9019\u53ef\u80fd\u5c0e\u81f4\u300c\u9ad2\u8b80\u300d\uff08Dirty Read\uff09\u73fe\u8c61\uff0c\u5373\u8b80\u53d6\u5230\u4e0d\u4e00\u81f4\u7684\u6578\u64da\u3002<\/li>\n<li><strong>\u8b80\u53d6\u5df2\u63d0\u4ea4\uff08Read Committed\uff09<\/strong>: \u5728\u9019\u500b\u7d1a\u5225\u4e0b\uff0c\u4e8b\u52d9\u53ea\u80fd\u8b80\u53d6\u5df2\u63d0\u4ea4\u7684\u6578\u64da\u3002\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u9ad2\u8b80\uff0c\u4f46\u4ecd\u7136\u53ef\u80fd\u51fa\u73fe\u300c\u4e0d\u53ef\u91cd\u8907\u8b80\u53d6\u300d\uff08Non-repeatable Read\uff09\u73fe\u8c61\u3002<\/li>\n<li><strong>\u53ef\u91cd\u8907\u8b80\u53d6\uff08Repeatable Read\uff09<\/strong>: \u6b64\u7d1a\u5225\u78ba\u4fdd\u5728\u540c\u4e00\u4e8b\u52d9\u4e2d\u591a\u6b21\u8b80\u53d6\u76f8\u540c\u7684\u6578\u64da\u6642\uff0c\u7d50\u679c\u662f\u4e00\u81f4\u7684\u3002\u9019\u53ef\u4ee5\u9632\u6b62\u4e0d\u53ef\u91cd\u8907\u8b80\u53d6\uff0c\u4f46\u4ecd\u7136\u53ef\u80fd\u51fa\u73fe\u300c\u5e7b\u8b80\u300d\uff08Phantom Read\uff09\u73fe\u8c61\u3002<\/li>\n<li><strong>\u5e8f\u5217\u5316\uff08Serializable\uff09<\/strong>: \u9019\u662f\u6700\u9ad8\u7684\u9694\u96e2\u7d1a\u5225\uff0c\u78ba\u4fdd\u4e8b\u52d9\u4e4b\u9593\u5b8c\u5168\u9694\u96e2\u3002\u6240\u6709\u4e8b\u52d9\u90fd\u50cf\u662f\u4e32\u884c\u57f7\u884c\u7684\uff0c\u9019\u6a23\u53ef\u4ee5\u907f\u514d\u9ad2\u8b80\u3001\u4e0d\u53ef\u91cd\u8907\u8b80\u53d6\u548c\u5e7b\u8b80\uff0c\u4f46\u6027\u80fd\u53ef\u80fd\u6703\u53d7\u5230\u5f71\u97ff\u3002<\/li>\n<\/ul>\n<h2 id=\"%e9%9a%94%e9%9b%a2%e7%b4%9a%e5%88%a5%e7%9a%84%e5%bd%b1%e9%9f%bf-AIQtClVlyp\">\u9694\u96e2\u7d1a\u5225\u7684\u5f71\u97ff<\/h2>\n<p>\u9078\u64c7\u9069\u7576\u7684\u9694\u96e2\u7d1a\u5225\u5c0d\u65bc\u61c9\u7528\u7a0b\u5e8f\u7684\u6027\u80fd\u548c\u6578\u64da\u4e00\u81f4\u6027\u81f3\u95dc\u91cd\u8981\u3002\u4ee5\u4e0b\u662f\u4e0d\u540c\u9694\u96e2\u7d1a\u5225\u7684\u5f71\u97ff\uff1a<\/p>\n<ul>\n<li><strong>\u6027\u80fd<\/strong>: \u4f4e\u9694\u96e2\u7d1a\u5225\u901a\u5e38\u63d0\u4f9b\u66f4\u597d\u7684\u6027\u80fd\uff0c\u56e0\u70ba\u5b83\u5011\u5141\u8a31\u66f4\u591a\u7684\u4e26\u884c\u64cd\u4f5c\u3002\u7136\u800c\uff0c\u9019\u53ef\u80fd\u6703\u5c0e\u81f4\u6578\u64da\u4e0d\u4e00\u81f4\u3002<\/li>\n<li><strong>\u6578\u64da\u4e00\u81f4\u6027<\/strong>: \u9ad8\u9694\u96e2\u7d1a\u5225\u63d0\u4f9b\u66f4\u597d\u7684\u6578\u64da\u4e00\u81f4\u6027\uff0c\u4f46\u53ef\u80fd\u6703\u5c0e\u81f4\u6027\u80fd\u4e0b\u964d\uff0c\u7279\u5225\u662f\u5728\u9ad8\u4e26\u767c\u74b0\u5883\u4e2d\u3002<\/li>\n<li><strong>\u61c9\u7528\u5834\u666f<\/strong>: \u6839\u64da\u61c9\u7528\u7684\u9700\u6c42\uff0c\u958b\u767c\u8005\u9700\u8981\u5728\u6027\u80fd\u548c\u6578\u64da\u4e00\u81f4\u6027\u4e4b\u9593\u627e\u5230\u5e73\u8861\u3002\u4f8b\u5982\uff0c\u91d1\u878d\u61c9\u7528\u901a\u5e38\u9700\u8981\u9ad8\u4e00\u81f4\u6027\uff0c\u800c\u67d0\u4e9b\u5831\u544a\u61c9\u7528\u53ef\u80fd\u66f4\u95dc\u6ce8\u6027\u80fd\u3002<\/li>\n<\/ul>\n<h2 id=\"db2%e9%9a%94%e9%9b%a2%e7%b4%9a%e5%88%a5%e7%9a%84%e5%af%a6%e9%a9%97-AIQtClVlyp\">DB2\u9694\u96e2\u7d1a\u5225\u7684\u5be6\u9a57<\/h2>\n<p>\u70ba\u4e86\u66f4\u597d\u5730\u7406\u89e3DB2\u7684\u9694\u96e2\u7d1a\u5225\uff0c\u4ee5\u4e0b\u662f\u4e00\u500b\u7c21\u55ae\u7684\u5be6\u9a57\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u5728DB2\u4e2d\u8a2d\u7f6e\u548c\u6e2c\u8a66\u4e0d\u540c\u7684\u9694\u96e2\u7d1a\u5225\u3002<\/p>\n<pre><code>-- \u5275\u5efa\u6e2c\u8a66\u8868\nCREATE TABLE test_table (\n    id INT PRIMARY KEY,\n    value VARCHAR(100)\n);\n\n-- \u63d2\u5165\u521d\u59cb\u6578\u64da\nINSERT INTO test_table (id, value) VALUES (1, 'A');\nINSERT INTO test_table (id, value) VALUES (2, 'B');\n\n-- \u958b\u59cb\u4e8b\u52d91\nBEGIN;\n\n-- \u4e8b\u52d91\u66f4\u65b0\u6578\u64da\nUPDATE test_table SET value = 'C' WHERE id = 1;\n\n-- \u958b\u59cb\u4e8b\u52d92\nBEGIN;\n\n-- \u8a2d\u7f6e\u9694\u96e2\u7d1a\u5225\u70ba\u8b80\u53d6\u672a\u63d0\u4ea4\nSET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;\n\n-- \u4e8b\u52d92\u8b80\u53d6\u6578\u64da\nSELECT * FROM test_table;\n\n-- \u63d0\u4ea4\u4e8b\u52d92\nCOMMIT;\n\n-- \u63d0\u4ea4\u4e8b\u52d91\nCOMMIT;\n<\/code><\/pre>\n<p>\u5728\u9019\u500b\u5be6\u9a57\u4e2d\uff0c\u4e8b\u52d92\u5728\u4e8b\u52d91\u5c1a\u672a\u63d0\u4ea4\u7684\u60c5\u6cc1\u4e0b\u8b80\u53d6\u4e86\u6578\u64da\uff0c\u9019\u5c55\u793a\u4e86\u8b80\u53d6\u672a\u63d0\u4ea4\u9694\u96e2\u7d1a\u5225\u7684\u7279\u6027\u3002\u958b\u767c\u8005\u53ef\u4ee5\u6839\u64da\u5be6\u969b\u9700\u6c42\u8abf\u6574\u9694\u96e2\u7d1a\u5225\uff0c\u4ee5\u9054\u5230\u6700\u4f73\u7684\u6027\u80fd\u548c\u6578\u64da\u4e00\u81f4\u6027\u3002<\/p>\n<h2 id=\"%e7%b5%90%e8%ab%96-AIQtClVlyp\">\u7d50\u8ad6<\/h2>\n<p>DB2\u7684\u9694\u96e2\u7d1a\u5225\u662f\u8cc7\u6599\u5eab\u8a2d\u8a08\u4e2d\u4e00\u500b\u91cd\u8981\u7684\u8003\u91cf\u56e0\u7d20\u3002\u4e86\u89e3\u4e0d\u540c\u9694\u96e2\u7d1a\u5225\u7684\u7279\u6027\u53ca\u5176\u5c0d\u6027\u80fd\u548c\u6578\u64da\u4e00\u81f4\u6027\u7684\u5f71\u97ff\uff0c\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u505a\u51fa\u66f4\u660e\u667a\u7684\u6c7a\u7b56\u3002\u5728\u9078\u64c7\u9069\u5408\u7684\u9694\u96e2\u7d1a\u5225\u6642\uff0c\u61c9\u6839\u64da\u5177\u9ad4\u7684\u61c9\u7528\u9700\u6c42\u9032\u884c\u8a55\u4f30\u3002<\/p>\n<p>\u5982\u9700\u4e86\u89e3\u66f4\u591a\u6709\u95dc<code><a href=\"https:\/\/server.hk\">VPS<\/a><\/code>\u548c<code><a href=\"https:\/\/server.hk\">\u9999\u6e2f\u4f3a\u670d\u5668<\/a><\/code>\u7684\u8cc7\u8a0a\uff0c\u8acb\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22DB2\u9694\u96e2\u7d1a\u7684\u89e3\u8b80\u8207\u8a66\u9a57\uff0c\u6df1\u5165\u4e86\u89e3\u5176\u5c0d\u6578\u64da\u4e00\u81f4\u6027\u548c\u4e26\u767c\u6027\u7684\u5f71\u97ff\uff0c\u63d0\u5347\u6578\u64da\u5eab\u7ba1\u7406\u6280\u80fd\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-158763","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/158763","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=158763"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/158763\/revisions"}],"predecessor-version":[{"id":158764,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/158763\/revisions\/158764"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=158763"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=158763"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=158763"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}