{"id":96888,"date":"2024-10-20T13:12:17","date_gmt":"2024-10-20T05:12:17","guid":{"rendered":"https:\/\/server.hk\/cnblog\/96888\/"},"modified":"2024-10-20T13:12:18","modified_gmt":"2024-10-20T05:12:18","slug":"postgresql-%e7%9a%84-mvcc-%e6%a9%9f%e5%88%b6%e8%a7%a3%e6%9e%90","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/96888\/","title":{"rendered":"PostgreSQL \u7684 MVCC \u6a5f\u5236\u89e3\u6790"},"content":{"rendered":"<h1 id=\"postgresql-%e7%9a%84-mvcc-%e6%a9%9f%e5%88%b6%e8%a7%a3%e6%9e%90-evWYSpWRIK\">PostgreSQL \u7684 MVCC \u6a5f\u5236\u89e3\u6790<\/h1>\n<p>\u5728\u7576\u4eca\u7684\u6578\u64da\u5eab\u7ba1\u7406\u7cfb\u7d71\u4e2d\uff0cPostgreSQL \u4ee5\u5176\u5f37\u5927\u7684\u529f\u80fd\u548c\u9748\u6d3b\u6027\u800c\u805e\u540d\u3002\u5176\u4e2d\uff0cMVCC\uff08\u591a\u7248\u672c\u4e26\u767c\u63a7\u5236\uff09\u662f\u5176\u6838\u5fc3\u7279\u6027\u4e4b\u4e00\uff0c\u80fd\u5920\u6709\u6548\u5730\u8655\u7406\u4e26\u767c\u4e8b\u52d9\uff0c\u4e26\u78ba\u4fdd\u6578\u64da\u7684\u4e00\u81f4\u6027\u548c\u5b8c\u6574\u6027\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e PostgreSQL \u7684 MVCC \u6a5f\u5236\uff0c\u4e26\u5206\u6790\u5176\u5de5\u4f5c\u539f\u7406\u53ca\u512a\u52e2\u3002<\/p>\n<h2 id=\"%e4%bb%80%e9%ba%bc%e6%98%af-mvcc%ef%bc%9f-evWYSpWRIK\">\u4ec0\u9ebc\u662f MVCC\uff1f<\/h2>\n<p>MVCC\uff0c\u5373\u591a\u7248\u672c\u4e26\u767c\u63a7\u5236\uff0c\u662f\u4e00\u7a2e\u7528\u65bc\u7ba1\u7406\u6578\u64da\u5eab\u4e2d\u591a\u500b\u4e8b\u52d9\u540c\u6642\u8a2a\u554f\u6578\u64da\u7684\u6280\u8853\u3002\u5b83\u5141\u8a31\u4e8b\u52d9\u5728\u4e0d\u4e92\u76f8\u5e72\u64fe\u7684\u60c5\u6cc1\u4e0b\u9032\u884c\u64cd\u4f5c\uff0c\u5f9e\u800c\u63d0\u9ad8\u4e86\u6578\u64da\u5eab\u7684\u6027\u80fd\u548c\u53ef\u64f4\u5c55\u6027\u3002\u5728 MVCC \u4e2d\uff0c\u6bcf\u7576\u6578\u64da\u88ab\u4fee\u6539\u6642\uff0c\u7cfb\u7d71\u6703\u5275\u5efa\u8a72\u6578\u64da\u7684\u65b0\u7248\u672c\uff0c\u800c\u4e0d\u662f\u76f4\u63a5\u8986\u84cb\u820a\u7248\u672c\u3002\u9019\u6a23\uff0c\u8b80\u53d6\u64cd\u4f5c\u53ef\u4ee5\u8a2a\u554f\u820a\u7248\u672c\u7684\u6578\u64da\uff0c\u800c\u4e0d\u6703\u53d7\u5230\u5beb\u5165\u64cd\u4f5c\u7684\u5f71\u97ff\u3002<\/p>\n<h2 id=\"postgresql-%e4%b8%ad%e7%9a%84-mvcc-%e5%b7%a5%e4%bd%9c%e5%8e%9f%e7%90%86-evWYSpWRIK\">PostgreSQL \u4e2d\u7684 MVCC \u5de5\u4f5c\u539f\u7406<\/h2>\n<p>\u5728 PostgreSQL \u4e2d\uff0cMVCC \u7684\u5be6\u73fe\u4f9d\u8cf4\u65bc\u4ee5\u4e0b\u5e7e\u500b\u95dc\u9375\u6982\u5ff5\uff1a<\/p>\n<ul>\n<li><strong>\u4e8b\u52d9 ID\uff08Transaction ID\uff09<\/strong>\uff1a\u6bcf\u500b\u4e8b\u52d9\u5728\u958b\u59cb\u6642\u6703\u7372\u5f97\u4e00\u500b\u552f\u4e00\u7684\u4e8b\u52d9 ID\uff0c\u9019\u500b ID \u7528\u65bc\u6a19\u8b58\u8a72\u4e8b\u52d9\u7684\u7248\u672c\u3002<\/li>\n<li><strong>\u5feb\u7167\uff08Snapshot\uff09<\/strong>\uff1a\u6bcf\u500b\u4e8b\u52d9\u5728\u958b\u59cb\u6642\u6703\u7372\u5f97\u4e00\u500b\u5feb\u7167\uff0c\u9019\u500b\u5feb\u7167\u8a18\u9304\u4e86\u7576\u524d\u6d3b\u8e8d\u4e8b\u52d9\u7684\u72c0\u614b\u3002\u9019\u4f7f\u5f97\u4e8b\u52d9\u80fd\u5920\u5728\u5176\u958b\u59cb\u6642\u770b\u5230\u4e00\u81f4\u7684\u6578\u64da\u8996\u5716\u3002<\/li>\n<li><strong>\u53ef\u898b\u6027\uff08Visibility\uff09<\/strong>\uff1a\u6bcf\u500b\u6578\u64da\u884c\u90fd\u6709\u4e00\u500b\u8207\u4e4b\u76f8\u95dc\u7684\u4e8b\u52d9 ID\uff0c\u9019\u500b ID \u7528\u65bc\u5224\u65b7\u8a72\u884c\u5c0d\u65bc\u7576\u524d\u4e8b\u52d9\u662f\u5426\u53ef\u898b\u3002\u7576\u4e00\u500b\u4e8b\u52d9\u67e5\u8a62\u6578\u64da\u6642\uff0c\u7cfb\u7d71\u6703\u6839\u64da\u5feb\u7167\u548c\u4e8b\u52d9 ID \u4f86\u6c7a\u5b9a\u54ea\u4e9b\u7248\u672c\u7684\u6578\u64da\u662f\u53ef\u898b\u7684\u3002<\/li>\n<\/ul>\n<h3 id=\"%e6%95%b8%e6%93%9a%e8%a1%8c%e7%9a%84%e7%89%88%e6%9c%ac%e7%ae%a1%e7%90%86-evWYSpWRIK\">\u6578\u64da\u884c\u7684\u7248\u672c\u7ba1\u7406<\/h3>\n<p>\u5728 PostgreSQL \u4e2d\uff0c\u6578\u64da\u884c\u7684\u7248\u672c\u7ba1\u7406\u662f\u901a\u904e\u5728\u6bcf\u500b\u6578\u64da\u884c\u4e2d\u5b58\u5132\u5169\u500b\u4e8b\u52d9 ID \u4f86\u5be6\u73fe\u7684\uff1a\u4e00\u500b\u662f\u8a72\u884c\u7684\u5275\u5efa\u4e8b\u52d9 ID\uff0c\u53e6\u4e00\u500b\u662f\u8a72\u884c\u7684\u522a\u9664\u4e8b\u52d9 ID\u3002\u7576\u4e00\u500b\u4e8b\u52d9\u4fee\u6539\u6578\u64da\u884c\u6642\uff0c\u7cfb\u7d71\u6703\u5275\u5efa\u4e00\u500b\u65b0\u7684\u7248\u672c\uff0c\u4e26\u66f4\u65b0\u9019\u4e9b\u4e8b\u52d9 ID\u3002<\/p>\n<pre><code>-- \u5275\u5efa\u4e00\u500b\u8868\nCREATE TABLE example (\n    id SERIAL PRIMARY KEY,\n    data TEXT\n);\n\n-- \u63d2\u5165\u6578\u64da\nINSERT INTO example (data) VALUES ('\u7248\u672c 1');\n\n-- \u66f4\u65b0\u6578\u64da\nUPDATE example SET data = '\u7248\u672c 2' WHERE id = 1;\n<\/code><\/pre>\n<p>\u5728\u4e0a\u8ff0\u793a\u4f8b\u4e2d\uff0c\u7576\u66f4\u65b0\u64cd\u4f5c\u57f7\u884c\u6642\uff0cPostgreSQL \u6703\u5275\u5efa\u4e00\u500b\u65b0\u7684\u6578\u64da\u884c\u7248\u672c\uff0c\u4e26\u5c07\u539f\u59cb\u7248\u672c\u6a19\u8a18\u70ba\u4e0d\u53ef\u898b\u3002\u9019\u6a23\uff0c\u4efb\u4f55\u5728\u66f4\u65b0\u4e4b\u524d\u958b\u59cb\u7684\u4e8b\u52d9\u4ecd\u7136\u53ef\u4ee5\u8a2a\u554f\u539f\u59cb\u7248\u672c\u7684\u6578\u64da\u3002<\/p>\n<h2 id=\"mvcc-%e7%9a%84%e5%84%aa%e5%8b%a2-evWYSpWRIK\">MVCC \u7684\u512a\u52e2<\/h2>\n<p>PostgreSQL \u7684 MVCC \u6a5f\u5236\u5e36\u4f86\u4e86\u591a\u9805\u512a\u52e2\uff1a<\/p>\n<ul>\n<li><strong>\u63d0\u9ad8\u4e26\u767c\u6027<\/strong>\uff1a\u7531\u65bc\u8b80\u53d6\u64cd\u4f5c\u4e0d\u6703\u88ab\u5beb\u5165\u64cd\u4f5c\u963b\u585e\uff0cMVCC \u5141\u8a31\u591a\u500b\u4e8b\u52d9\u540c\u6642\u9032\u884c\uff0c\u5f9e\u800c\u63d0\u9ad8\u4e86\u7cfb\u7d71\u7684\u6574\u9ad4\u6027\u80fd\u3002<\/li>\n<li><strong>\u6578\u64da\u4e00\u81f4\u6027<\/strong>\uff1aMVCC \u78ba\u4fdd\u4e86\u4e8b\u52d9\u5728\u57f7\u884c\u904e\u7a0b\u4e2d\u80fd\u5920\u770b\u5230\u4e00\u81f4\u7684\u6578\u64da\u8996\u5716\uff0c\u9019\u5c0d\u65bc\u4fdd\u6301\u6578\u64da\u7684\u5b8c\u6574\u6027\u81f3\u95dc\u91cd\u8981\u3002<\/li>\n<li><strong>\u7c21\u5316\u9396\u7ba1\u7406<\/strong>\uff1a\u7531\u65bc\u8b80\u53d6\u64cd\u4f5c\u4e0d\u9700\u8981\u9396\u5b9a\u6578\u64da\uff0cMVCC \u6e1b\u5c11\u4e86\u9396\u7684\u4f7f\u7528\uff0c\u5f9e\u800c\u964d\u4f4e\u4e86\u6b7b\u9396\u7684\u98a8\u96aa\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-evWYSpWRIK\">\u7e3d\u7d50<\/h2>\n<p>PostgreSQL \u7684 MVCC \u6a5f\u5236\u662f\u4e00\u7a2e\u5f37\u5927\u7684\u4e26\u767c\u63a7\u5236\u6280\u8853\uff0c\u80fd\u5920\u6709\u6548\u5730\u7ba1\u7406\u591a\u500b\u4e8b\u52d9\u7684\u540c\u6642\u8a2a\u554f\u3002\u901a\u904e\u5275\u5efa\u6578\u64da\u7684\u591a\u500b\u7248\u672c\uff0cMVCC \u4e0d\u50c5\u63d0\u9ad8\u4e86\u7cfb\u7d71\u7684\u6027\u80fd\uff0c\u9084\u78ba\u4fdd\u4e86\u6578\u64da\u7684\u4e00\u81f4\u6027\u548c\u5b8c\u6574\u6027\u3002\u5c0d\u65bc\u9700\u8981\u9ad8\u4e26\u767c\u548c\u9ad8\u53ef\u7528\u6027\u7684\u61c9\u7528\u5834\u666f\uff0cPostgreSQL \u7684 MVCC \u6a5f\u5236\u7121\u7591\u662f\u4e00\u500b\u7406\u60f3\u7684\u9078\u64c7\u3002<\/p>\n<p>\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u7a69\u5b9a\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2f VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\uff0c\u6eff\u8db3\u4e0d\u540c\u9700\u6c42\u7684\u5ba2\u6236\u3002\u7121\u8ad6\u662f\u6578\u64da\u5eab\u7ba1\u7406\u9084\u662f\u61c9\u7528\u90e8\u7f72\uff0c\u6211\u5011\u7684 <a href=\"https:\/\/server.hk\">\u4e91\u4f3a\u670d\u5668<\/a> \u90fd\u80fd\u70ba\u60a8\u63d0\u4f9b\u53ef\u9760\u7684\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u6df1\u5165\u89e3\u6790 PostgreSQL \u7684 MVCC \u6a5f\u5236\uff0c\u4e86\u89e3\u5176\u5982\u4f55\u5be6\u73fe\u9ad8\u6548\u7684\u4f75\u767c\u63a7\u5236\u8207\u6578\u64da\u4e00\u81f4\u6027\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-96888","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96888","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=96888"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96888\/revisions"}],"predecessor-version":[{"id":96889,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/96888\/revisions\/96889"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=96888"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=96888"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=96888"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}