{"id":59585,"date":"2024-10-12T23:12:12","date_gmt":"2024-10-12T15:12:12","guid":{"rendered":"https:\/\/server.hk\/cnblog\/59585\/"},"modified":"2024-10-12T23:12:12","modified_gmt":"2024-10-12T15:12:12","slug":"citus-%e5%88%86%e4%bd%88%e5%bc%8f-postgresql-%e9%9b%86%e7%be%a4-sql-referencesql%e6%94%af%e6%8c%81%e5%92%8c%e8%ae%8a%e9%80%9a%e6%96%b9%e6%a1%88","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/59585\/","title":{"rendered":"Citus \u5206\u4f48\u5f0f PostgreSQL \u96c6\u7fa4 &#8211; SQL Reference(SQL\u652f\u6301\u548c\u8b8a\u901a\u65b9\u6848)"},"content":{"rendered":"<h1 id=\"citus-%e5%88%86%e4%bd%88%e5%bc%8f-postgresql-%e9%9b%86%e7%be%a4-sql-referencesql%e6%94%af%e6%8c%81%e5%92%8c%e8%ae%8a%e9%80%9a%e6%96%b9%e6%a1%88-AkSxyIGjjh\">Citus \u5206\u4f48\u5f0f PostgreSQL \u96c6\u7fa4 &#8211; SQL Reference(SQL\u652f\u6301\u548c\u8b8a\u901a\u65b9\u6848)<\/h1>\n<p>\u5728\u7576\u4eca\u6578\u64da\u9a45\u52d5\u7684\u4e16\u754c\u4e2d\uff0c\u4f01\u696d\u5c0d\u65bc\u6578\u64da\u5eab\u7684\u9700\u6c42\u65e5\u76ca\u589e\u52a0\u3002PostgreSQL \u4f5c\u70ba\u4e00\u500b\u5f37\u5927\u7684\u958b\u6e90\u95dc\u4fc2\u578b\u6578\u64da\u5eab\u7cfb\u7d71\uff0c\u56e0\u5176\u7a69\u5b9a\u6027\u548c\u64f4\u5c55\u6027\u800c\u53d7\u5230\u5ee3\u6cdb\u4f7f\u7528\u3002Citus \u662f\u4e00\u500b\u57fa\u65bc PostgreSQL \u7684\u64f4\u5c55\uff0c\u65e8\u5728\u5c07\u5176\u8f49\u8b8a\u70ba\u4e00\u500b\u5206\u4f48\u5f0f\u6578\u64da\u5eab\uff0c\u80fd\u5920\u8655\u7406\u5927\u898f\u6a21\u7684\u6578\u64da\u96c6\u548c\u9ad8\u4e26\u767c\u7684\u67e5\u8a62\u9700\u6c42\u3002\u672c\u6587\u5c07\u63a2\u8a0e Citus \u7684 SQL \u652f\u6301\u53ca\u5176\u8b8a\u901a\u65b9\u6848\u3002<\/p>\n<h2 id=\"citus-%e7%9a%84%e6%9e%b6%e6%a7%8b-AkSxyIGjjh\">Citus \u7684\u67b6\u69cb<\/h2>\n<p>Citus \u901a\u904e\u5c07\u6578\u64da\u5206\u7247\uff08sharding\uff09\u4f86\u5be6\u73fe\u5206\u4f48\u5f0f\u67b6\u69cb\u3002\u9019\u610f\u5473\u8457\u6578\u64da\u88ab\u5206\u6563\u5230\u591a\u500b\u7bc0\u9ede\u4e0a\uff0c\u5f9e\u800c\u63d0\u9ad8\u4e86\u67e5\u8a62\u6027\u80fd\u548c\u53ef\u64f4\u5c55\u6027\u3002Citus \u7684\u67b6\u69cb\u4e3b\u8981\u7531\u4ee5\u4e0b\u5e7e\u500b\u7d44\u4ef6\u7d44\u6210\uff1a<\/p>\n<ul>\n<li><strong>Coordinator Node\uff1a<\/strong>\u8ca0\u8cac\u63a5\u6536\u5ba2\u6236\u7aef\u7684\u8acb\u6c42\uff0c\u4e26\u5c07\u67e5\u8a62\u5206\u767c\u5230\u76f8\u61c9\u7684\u5de5\u4f5c\u7bc0\u9ede\u3002<\/li>\n<li><strong>Worker Nodes\uff1a<\/strong>\u5be6\u969b\u5b58\u5132\u6578\u64da\u4e26\u57f7\u884c\u67e5\u8a62\u7684\u7bc0\u9ede\u3002<\/li>\n<li><strong>Shards\uff1a<\/strong>\u6578\u64da\u7684\u5206\u7247\uff0c\u6bcf\u500b shard \u53ef\u4ee5\u5b58\u5132\u5728\u4e0d\u540c\u7684 worker node \u4e0a\u3002<\/li>\n<\/ul>\n<h2 id=\"sql-%e6%94%af%e6%8c%81-AkSxyIGjjh\">SQL \u652f\u6301<\/h2>\n<p>Citus \u652f\u6301 PostgreSQL \u7684\u5927\u90e8\u5206 SQL \u8a9e\u6cd5\uff0c\u9019\u4f7f\u5f97\u7528\u6236\u53ef\u4ee5\u8f15\u9b06\u5730\u5c07\u73fe\u6709\u7684 PostgreSQL \u61c9\u7528\u7a0b\u5e8f\u9077\u79fb\u5230 Citus\u3002\u4ee5\u4e0b\u662f\u4e00\u4e9b Citus \u652f\u6301\u7684 SQL \u7279\u6027\uff1a<\/p>\n<ul>\n<li><strong>\u6a19\u6e96 SQL \u67e5\u8a62\uff1a<\/strong>\u7528\u6236\u53ef\u4ee5\u4f7f\u7528 SELECT\u3001INSERT\u3001UPDATE \u548c DELETE \u7b49\u6a19\u6e96 SQL \u8a9e\u53e5\u3002<\/li>\n<li><strong>\u805a\u5408\u51fd\u6578\uff1a<\/strong>Citus \u652f\u6301\u591a\u7a2e\u805a\u5408\u51fd\u6578\uff0c\u5982 COUNT\u3001SUM\u3001AVG \u7b49\uff0c\u9019\u4e9b\u51fd\u6578\u53ef\u4ee5\u5728\u5206\u4f48\u5f0f\u74b0\u5883\u4e2d\u6709\u6548\u904b\u884c\u3002<\/li>\n<li><strong>JOIN \u64cd\u4f5c\uff1a<\/strong>Citus \u652f\u6301\u5728\u4e0d\u540c shards \u4e4b\u9593\u9032\u884c JOIN \u64cd\u4f5c\uff0c\u4f46\u9700\u8981\u6ce8\u610f\u6027\u80fd\u5f71\u97ff\u3002<\/li>\n<\/ul>\n<h3 id=\"%e6%9f%a5%e8%a9%a2%e7%a4%ba%e4%be%8b-AkSxyIGjjh\">\u67e5\u8a62\u793a\u4f8b<\/h3>\n<p>\u4ee5\u4e0b\u662f\u4e00\u500b\u7c21\u55ae\u7684\u67e5\u8a62\u793a\u4f8b\uff0c\u5c55\u793a\u5982\u4f55\u5728 Citus \u4e2d\u4f7f\u7528 SQL\uff1a<\/p>\n<pre><code>SELECT user_id, COUNT(*)\nFROM events\nGROUP BY user_id\nORDER BY COUNT(*) DESC;<\/code><\/pre>\n<p>\u9019\u500b\u67e5\u8a62\u5c07\u8fd4\u56de\u6bcf\u500b\u7528\u6236\u7684\u4e8b\u4ef6\u6578\u91cf\uff0c\u4e26\u6309\u6578\u91cf\u964d\u5e8f\u6392\u5217\u3002Citus \u5c07\u81ea\u52d5\u8655\u7406\u6578\u64da\u7684\u5206\u7247\u548c\u805a\u5408\u3002<\/p>\n<h2 id=\"%e8%ae%8a%e9%80%9a%e6%96%b9%e6%a1%88-AkSxyIGjjh\">\u8b8a\u901a\u65b9\u6848<\/h2>\n<p>\u5118\u7ba1 Citus \u63d0\u4f9b\u4e86\u5f37\u5927\u7684 SQL \u652f\u6301\uff0c\u4f46\u5728\u67d0\u4e9b\u60c5\u6cc1\u4e0b\uff0c\u53ef\u80fd\u9700\u8981\u8003\u616e\u8b8a\u901a\u65b9\u6848\u4ee5\u63d0\u9ad8\u6027\u80fd\u6216\u89e3\u6c7a\u7279\u5b9a\u554f\u984c\uff1a<\/p>\n<ul>\n<li><strong>\u4f7f\u7528\u5206\u5340\u8868\uff1a<\/strong>\u5c0d\u65bc\u67d0\u4e9b\u67e5\u8a62\uff0c\u4f7f\u7528 PostgreSQL \u7684\u5206\u5340\u8868\u529f\u80fd\u53ef\u4ee5\u63d0\u9ad8\u6027\u80fd\uff0c\u7279\u5225\u662f\u5728\u8655\u7406\u5927\u91cf\u6578\u64da\u6642\u3002<\/li>\n<li><strong>\u8abf\u6574\u67e5\u8a62\u8a08\u5283\uff1a<\/strong>\u7528\u6236\u53ef\u4ee5\u4f7f\u7528 EXPLAIN \u547d\u4ee4\u4f86\u5206\u6790\u67e5\u8a62\u8a08\u5283\uff0c\u4e26\u6839\u64da\u9700\u8981\u9032\u884c\u8abf\u6574\uff0c\u4ee5\u512a\u5316\u6027\u80fd\u3002<\/li>\n<li><strong>\u4f7f\u7528 Citus \u7684\u5206\u4f48\u5f0f\u51fd\u6578\uff1a<\/strong>\u5229\u7528 Citus \u63d0\u4f9b\u7684\u5206\u4f48\u5f0f\u51fd\u6578\u4f86\u7c21\u5316\u67e5\u8a62\u548c\u6578\u64da\u64cd\u4f5c\u3002<\/li>\n<\/ul>\n<h2 id=\"%e7%b8%bd%e7%b5%90-AkSxyIGjjh\">\u7e3d\u7d50<\/h2>\n<p>Citus \u4f5c\u70ba\u4e00\u500b\u5f37\u5927\u7684\u5206\u4f48\u5f0f PostgreSQL \u89e3\u6c7a\u65b9\u6848\uff0c\u63d0\u4f9b\u4e86\u5ee3\u6cdb\u7684 SQL \u652f\u6301\u548c\u9748\u6d3b\u7684\u8b8a\u901a\u65b9\u6848\uff0c\u4f7f\u5f97\u7528\u6236\u80fd\u5920\u5728\u5927\u898f\u6a21\u6578\u64da\u74b0\u5883\u4e2d\u9ad8\u6548\u904b\u884c\u3002\u7121\u8ad6\u662f\u8655\u7406\u9ad8\u4e26\u767c\u67e5\u8a62\u9084\u662f\u7ba1\u7406\u5927\u6578\u64da\u96c6\uff0cCitus \u90fd\u80fd\u63d0\u4f9b\u7a69\u5b9a\u7684\u6027\u80fd\u548c\u53ef\u64f4\u5c55\u6027\u3002\u5982\u679c\u60a8\u6b63\u5728\u5c0b\u627e\u53ef\u9760\u7684 <a href=\"https:\/\/server.hk\">\u9999\u6e2f VPS<\/a> \u89e3\u6c7a\u65b9\u6848\uff0cServer.HK \u63d0\u4f9b\u591a\u7a2e\u9078\u64c7\u4ee5\u6eff\u8db3\u60a8\u7684\u9700\u6c42\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u63a2\u7d22 Citus \u5206\u4f48\u5f0f PostgreSQL \u96c6\u7fa4\u7684 SQL \u53c3\u8003\uff0c\u4e86\u89e3\u5176 SQL \u652f\u6301\u53ca\u8b8a\u901a\u65b9\u6848\uff0c\u63d0\u5347\u6578\u64da\u8655\u7406\u6548\u7387\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-59585","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/59585","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=59585"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/59585\/revisions"}],"predecessor-version":[{"id":59586,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/59585\/revisions\/59586"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=59585"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=59585"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=59585"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}