{"id":61425,"date":"2024-10-13T11:01:34","date_gmt":"2024-10-13T03:01:34","guid":{"rendered":"https:\/\/server.hk\/cnblog\/61425\/"},"modified":"2024-10-13T11:01:34","modified_gmt":"2024-10-13T03:01:34","slug":"flink-sql-%e7%9f%a5%e5%85%b6%e6%89%80%e4%bb%a5%e7%84%b6%ef%bc%9aexplain%e3%80%81show%e3%80%81load%e3%80%81set-%e5%ad%90%e5%8f%a5","status":"publish","type":"post","link":"https:\/\/server.hk\/cnblog\/61425\/","title":{"rendered":"Flink SQL \u77e5\u5176\u6240\u4ee5\u7136\uff1aExplain\u3001Show\u3001Load\u3001Set \u5b50\u53e5"},"content":{"rendered":"

Flink SQL \u77e5\u5176\u6240\u4ee5\u7136\uff1aExplain\u3001Show\u3001Load\u3001Set \u5b50\u53e5<\/h1>\n

Apache Flink \u662f\u4e00\u500b\u5f37\u5927\u7684\u6d41\u8655\u7406\u6846\u67b6\uff0c\u5ee3\u6cdb\u61c9\u7528\u65bc\u5927\u6578\u64da\u8655\u7406\u548c\u5be6\u6642\u6578\u64da\u5206\u6790\u3002Flink SQL \u4f5c\u70ba\u5176\u4e00\u90e8\u5206\uff0c\u63d0\u4f9b\u4e86\u4e00\u7a2e\u7c21\u55ae\u800c\u76f4\u89c0\u7684\u65b9\u5f0f\u4f86\u67e5\u8a62\u548c\u8655\u7406\u6578\u64da\u3002\u672c\u6587\u5c07\u6df1\u5165\u63a2\u8a0e Flink SQL \u4e2d\u7684\u56db\u500b\u91cd\u8981\u5b50\u53e5\uff1aExplain\u3001Show\u3001Load \u548c Set\uff0c\u5e6b\u52a9\u8b80\u8005\u66f4\u597d\u5730\u7406\u89e3\u5176\u529f\u80fd\u548c\u7528\u6cd5\u3002<\/p>\n

1. Explain \u5b50\u53e5<\/h2>\n

\u5728 Flink SQL \u4e2d\uff0cEXPLAIN<\/code> \u5b50\u53e5\u7528\u65bc\u986f\u793a\u67e5\u8a62\u7684\u57f7\u884c\u8a08\u5283\u3002\u9019\u5c0d\u65bc\u512a\u5316\u67e5\u8a62\u6027\u80fd\u81f3\u95dc\u91cd\u8981\uff0c\u56e0\u70ba\u5b83\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u7406\u89e3\u67e5\u8a62\u7684\u57f7\u884c\u908f\u8f2f\u548c\u6f5b\u5728\u7684\u6027\u80fd\u74f6\u9838\u3002<\/p>\n

EXPLAIN SELECT * FROM my_table WHERE id > 10;<\/code><\/pre>\n
\u57f7\u884c\u4e0a\u8ff0\u67e5\u8a62\u5f8c\uff0cFlink \u5c07\u8fd4\u56de\u4e00\u500b\u8a73\u7d30\u7684\u57f7\u884c\u8a08\u5283\uff0c\u5305\u62ec\u5404\u500b\u64cd\u4f5c\u7684\u985e\u578b\u3001\u6578\u64da\u6d41\u7684\u8def\u5f91\u4ee5\u53ca\u6240\u9700\u7684\u8cc7\u6e90\u3002\u9019\u4e9b\u4fe1\u606f\u53ef\u4ee5\u5e6b\u52a9\u958b\u767c\u8005\u8abf\u6574\u67e5\u8a62\u4ee5\u63d0\u9ad8\u6027\u80fd\u3002<\/p>\n
2. Show \u5b50\u53e5<\/h2>\n
SHOW<\/code> \u5b50\u53e5\u7528\u65bc\u986f\u793a\u8cc7\u6599\u5eab\u4e2d\u7684\u5404\u7a2e\u5143\u6578\u64da\u3002\u9019\u5305\u62ec\u8868\u3001\u8996\u5716\u3001\u51fd\u6578\u7b49\u7684\u5217\u8868\u3002\u9019\u5c0d\u65bc\u4e86\u89e3\u7576\u524d\u74b0\u5883\u4e2d\u7684\u53ef\u7528\u8cc7\u6e90\u975e\u5e38\u6709\u7528\u3002<\/p>\n
SHOW TABLES;<\/code><\/pre>\n
\u57f7\u884c\u4e0a\u8ff0\u547d\u4ee4\u5c07\u5217\u51fa\u7576\u524d\u8cc7\u6599\u5eab\u4e2d\u7684\u6240\u6709\u8868\u3002\u958b\u767c\u8005\u53ef\u4ee5\u4f7f\u7528\u9019\u4e9b\u4fe1\u606f\u4f86\u78ba\u8a8d\u8868\u7684\u5b58\u5728\u6027\u6216\u6aa2\u67e5\u5176\u7d50\u69cb\u3002<\/p>\n
3. Load \u5b50\u53e5<\/h2>\n
LOAD<\/code> \u5b50\u53e5\u7528\u65bc\u5f9e\u5916\u90e8\u8cc7\u6599\u6e90\u52a0\u8f09\u6578\u64da\u3002\u9019\u5c0d\u65bc\u9700\u8981\u5f9e\u4e0d\u540c\u4f86\u6e90\u6574\u5408\u6578\u64da\u7684\u61c9\u7528\u5834\u666f\u975e\u5e38\u91cd\u8981\u3002Flink \u652f\u6301\u591a\u7a2e\u8cc7\u6599\u4f86\u6e90\uff0c\u5305\u62ec CSV\u3001JSON\u3001Parquet \u7b49\u683c\u5f0f\u3002<\/p>\n
LOAD DATA INFILE 'data.csv' INTO TABLE my_table;<\/code><\/pre>\n
\u4e0a\u8ff0\u547d\u4ee4\u5c07\u5f9e\u6307\u5b9a\u7684 CSV \u6587\u4ef6\u4e2d\u52a0\u8f09\u6578\u64da\u5230 my_table<\/code> \u8868\u4e2d\u3002\u9019\u4f7f\u5f97\u6578\u64da\u7684\u5c0e\u5165\u8b8a\u5f97\u7c21\u55ae\u800c\u9ad8\u6548\u3002<\/p>\n
4. Set \u5b50\u53e5<\/h2>\n
SET<\/code> \u5b50\u53e5\u7528\u65bc\u8a2d\u7f6e Flink SQL \u7684\u914d\u7f6e\u53c3\u6578\u3002\u9019\u4e9b\u53c3\u6578\u53ef\u4ee5\u5f71\u97ff\u67e5\u8a62\u7684\u57f7\u884c\u65b9\u5f0f\u548c\u6027\u80fd\u3002\u4f8b\u5982\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u8abf\u6574\u4e26\u884c\u5ea6\u3001\u7de9\u885d\u5340\u5927\u5c0f\u7b49\u8a2d\u7f6e\u3002<\/p>\n
SET parallelism = 4;<\/code><\/pre>\n
\u57f7\u884c\u4e0a\u8ff0\u547d\u4ee4\u5c07\u67e5\u8a62\u7684\u4e26\u884c\u5ea6\u8a2d\u7f6e\u70ba 4\uff0c\u9019\u610f\u5473\u8457\u67e5\u8a62\u5c07\u5728\u56db\u500b\u4efb\u52d9\u4e2d\u4e26\u884c\u57f7\u884c\uff0c\u5f9e\u800c\u63d0\u9ad8\u8655\u7406\u901f\u5ea6\u3002<\/p>\n
\u7e3d\u7d50<\/h2>\n
Flink SQL \u63d0\u4f9b\u4e86\u5f37\u5927\u7684\u67e5\u8a62\u529f\u80fd\uff0c\u901a\u904e EXPLAIN<\/code>\u3001SHOW<\/code>\u3001LOAD<\/code> \u548c SET<\/code> \u5b50\u53e5\uff0c\u958b\u767c\u8005\u53ef\u4ee5\u66f4\u6709\u6548\u5730\u7ba1\u7406\u548c\u512a\u5316\u6578\u64da\u8655\u7406\u904e\u7a0b\u3002\u9019\u4e9b\u5b50\u53e5\u4e0d\u50c5\u63d0\u9ad8\u4e86\u67e5\u8a62\u7684\u9748\u6d3b\u6027\uff0c\u9084\u5e6b\u52a9\u958b\u767c\u8005\u6df1\u5165\u7406\u89e3\u6578\u64da\u6d41\u7684\u904b\u4f5c\u65b9\u5f0f\u3002<\/p>\n
\u5982\u679c\u60a8\u5c0d\u65bc\u5982\u4f55\u5728 \u9999\u6e2f VPS<\/a> \u74b0\u5883\u4e2d\u904b\u884c Flink SQL \u6709\u8208\u8da3\uff0c\u6216\u60f3\u4e86\u89e3\u66f4\u591a\u95dc\u65bc \u4e91\u670d\u52a1\u5668<\/a> \u7684\u4fe1\u606f\uff0c\u8acb\u96a8\u6642\u8a2a\u554f\u6211\u5011\u7684\u7db2\u7ad9\u4ee5\u7372\u53d6\u66f4\u591a\u8cc7\u6e90\u548c\u652f\u6301\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
Explore Flink SQL’s Explain, Show, Load, and Set clauses to enhance your data processing skills and optimize query performance effectively.<\/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-61425","post","type-post","status-publish","format-standard","hentry","category-database"],"_links":{"self":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/61425","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=61425"}],"version-history":[{"count":1,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/61425\/revisions"}],"predecessor-version":[{"id":61426,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/posts\/61425\/revisions\/61426"}],"wp:attachment":[{"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/media?parent=61425"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/categories?post=61425"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/server.hk\/cnblog\/wp-json\/wp\/v2\/tags?post=61425"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}