{"id":477314,"date":"2023-08-09T09:11:08","date_gmt":"2023-08-09T09:11:08","guid":{"rendered":""},"modified":"2023-09-05T11:14:30","modified_gmt":"2023-09-05T11:14:30","slug":"functional-dependency","status":"publish","type":"wiki","link":"https:\/\/oneproxy.pro\/cn\/wiki\/functional-dependency\/","title":{"rendered":"\u51fd\u6570\u4f9d\u8d56"},"content":{"rendered":"

\u51fd\u6570\u4f9d\u8d56\u662f\u6570\u636e\u5e93\u89c4\u8303\u5316\u9886\u57df\u7684\u6838\u5fc3\u539f\u5219\uff0c\u800c\u6570\u636e\u5e93\u89c4\u8303\u5316\u53c8\u662f\u6570\u636e\u5e93\u8bbe\u8ba1\u548c\u7ba1\u7406\u7684\u57fa\u672c\u7ec4\u6210\u90e8\u5206\u3002\u5b83\u7528\u4e8e\u6d88\u9664\u5197\u4f59\u5e76\u9632\u6b62\u53ef\u80fd\u7684\u4e0d\u4e00\u81f4\uff0c\u4ece\u800c\u63d0\u9ad8\u6570\u636e\u5e93\u7ba1\u7406\u7cfb\u7edf\u7684\u6548\u7387\u3002<\/p>\n

\u529f\u80fd\u4f9d\u8d56\u7684\u8d77\u6e90\uff1a\u5386\u53f2\u6982\u8ff0<\/h2>\n

\u51fd\u6570\u4f9d\u8d56\u7684\u6982\u5ff5\u6e90\u4e8e\u5173\u7cfb\u6570\u636e\u5e93\u7406\u8bba\u9886\u57df\u3002\u5b83\u7531 Edgar F. Codd \u4e8e 1970 \u5e74\u9996\u6b21\u5f15\u5165\uff0c\u4f5c\u4e3a\u4ed6\u5728\u6570\u636e\u5e93\u7ba1\u7406\u5173\u7cfb\u6a21\u578b\u65b9\u9762\u7684\u5f00\u521b\u6027\u5de5\u4f5c\u7684\u4e00\u90e8\u5206\u3002 Codd \u662f IBM \u7684\u8ba1\u7b97\u673a\u79d1\u5b66\u5bb6\uff0c\u8fd8\u56e0\u5176\u5bf9\u7ed3\u6784\u5316\u67e5\u8be2\u8bed\u8a00 (SQL)\uff08\u5173\u7cfb\u6570\u636e\u5e93\u7ba1\u7406\u7cfb\u7edf\u7684\u6807\u51c6\u8bed\u8a00\uff09\u5f00\u53d1\u7684\u91cd\u5927\u8d21\u732e\u800c\u53d7\u5230\u8ba4\u53ef\u3002<\/p>\n

\u6df1\u5165\u7814\u7a76\u51fd\u6570\u4f9d\u8d56<\/h2>\n

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\u51fd\u6570\u4f9d\u8d56\uff1a\u5e55\u540e\u82b1\u7d6e<\/h2>\n

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\u51fd\u6570\u4f9d\u8d56\u7684\u4e3b\u8981\u7279\u5f81<\/h2>\n

\u51fd\u6570\u4f9d\u8d56\u6709\u51e0\u4e2a\u5173\u952e\u7279\u5f81\uff1a<\/p>\n

    \n
  1. \u552f\u4e00\u6027\uff1a\u5982\u679c\u4e00\u7ec4\u5c5e\u6027 A \u5728\u529f\u80fd\u4e0a\u51b3\u5b9a B\uff0c\u5219\u6bcf\u4e2a A \u503c\u90fd\u6709\u4e00\u4e2a\u552f\u4e00\u7684 B \u503c\u3002<\/li>\n
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    \u4e0e\u76f8\u5173\u672f\u8bed\u7684\u6bd4\u8f83<\/h2>\n\n\n\n\n\n\n\n
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    \u4ee3\u7406\u670d\u52a1\u5668\u548c\u529f\u80fd\u4f9d\u8d56\u5173\u7cfb\u7684\u4ea4\u96c6<\/h2>\n

    \u867d\u7136\u529f\u80fd\u4f9d\u8d56\u6027\u4e3b\u8981\u4e0e\u6570\u636e\u5e93\u7ba1\u7406\u4e0a\u4e0b\u6587\u76f8\u5173\uff0c\u4f46\u4e0e\u4ee3\u7406\u670d\u52a1\u5668\u9886\u57df\u5b58\u5728\u5207\u7ebf\u5173\u7cfb\u3002\u5177\u4f53\u6765\u8bf4\uff0c\u4ee3\u7406\u670d\u52a1\u5668\u901a\u5e38\u4f7f\u7528\u6570\u636e\u5e93\u6765\u7ba1\u7406\u7528\u6237\u6570\u636e\u3001\u8bbf\u95ee\u63a7\u5236\u548c\u8bf7\u6c42\u65e5\u5fd7\u3002\u901a\u8fc7\u5e94\u7528\u529f\u80fd\u4f9d\u8d56\u539f\u5219\uff0c\u50cf OneProxy \u8fd9\u6837\u7684\u4ee3\u7406\u670d\u52a1\u63d0\u4f9b\u5546\u53ef\u4ee5\u4f18\u5316\u5176\u6570\u636e\u5e93\u7ed3\u6784\uff0c\u4ee5\u63d0\u9ad8\u6027\u80fd\u548c\u6570\u636e\u5b8c\u6574\u6027\u3002<\/p>\n

    \u76f8\u5173\u94fe\u63a5<\/h2>\n

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      \n
    1. Silberschatz\u3001Korth \u548c Sudarshan \u7684\u6570\u636e\u5e93\u7cfb\u7edf\u6982\u5ff5<\/a><\/li>\n
    2. DBMS \u4e2d\u7684\u51fd\u6570\u4f9d\u8d56\u5173\u7cfb \u2013 GeeksforGeeks<\/a><\/li>\n
    3. CJ Date \u7684\u6570\u636e\u5e93\u7cfb\u7edf\u7b80\u4ecb<\/a><\/li>\n
    4. Ramez Elmasri \u548c Shamkant B. Navathe \u7684\u300a\u6570\u636e\u5e93\u7cfb\u7edf\u57fa\u7840\u77e5\u8bc6\u300b<\/a><\/li>\n<\/ol>\n

      \u8bf7\u8bb0\u4f4f\uff0c\u5bf9\u51fd\u6570\u4f9d\u8d56\u5173\u7cfb\u7684\u7406\u89e3\u548c\u6b63\u786e\u5e94\u7528\u53ef\u4ee5\u5e26\u6765\u9ad8\u6548\u3001\u53ef\u9760\u548c\u53ef\u6269\u5c55\u7684\u6570\u636e\u5e93\u7cfb\u7edf\u3002<\/p>","protected":false},"featured_media":477315,"menu_order":0,"template":"","meta":{"_acf_changed":false,"content-type":"","inline_featured_image":false,"footnotes":""},"class_list":["post-477314","wiki","type-wiki","status-publish","has-post-thumbnail","hentry"],"acf":{"faq_title":"Frequently Asked Questions about Functional Dependency: A Fundamental Concept in Database Theory<\/mark>","faq_items":[{"question":"What is Functional Dependency?","answer":"

      Functional dependency is a core principle in the field of database normalization. It serves to eliminate redundancy and prevent possible inconsistency, thereby increasing the efficiency of database management systems.<\/p>"},{"question":"Who introduced the concept of Functional Dependency?","answer":"

      The concept of functional dependency was first introduced by Edgar F. Codd in 1970 as part of his groundbreaking work on the relational model for database management.<\/p>"},{"question":"How does Functional Dependency work in a relational database?","answer":"

      In a relational database, a set of attributes A functionally determines a set of attributes B if, for every valid instance of the database, all tuples with the same A-value also have the same B-value.<\/p>"},{"question":"What are Armstrong's Axioms?","answer":"

      Armstrong's Axioms are a set of rules that govern functional dependency. They include reflexivity, augmentation, and transitivity. These axioms are used to infer all the functional dependencies on a relational database.<\/p>"},{"question":"What are the key features of Functional Dependencies?","answer":"

      Functional dependencies have several key features: Uniqueness, Inference, Dependency preservation, and Lossless join.<\/p>"},{"question":"What are the different types of Functional Dependencies?","answer":"

      Functional dependencies can be categorized into various types: Trivial, Non-trivial, Completely non-trivial, and Transitive Dependency.<\/p>"},{"question":"What are the practical uses of Functional Dependencies?","answer":"

      Functional dependencies are used in database normalization, where they eliminate redundancy and improve data consistency. They help in preserving dependencies when a database is decomposed into multiple tables.<\/p>"},{"question":"What are the challenges related to Functional Dependencies?","answer":"

      Inferring functional dependencies from a large dataset can be computationally expensive and time-consuming. These problems can be mitigated by using a dependency inference algorithm.<\/p>"},{"question":"How are Functional Dependencies relevant to the future of database technologies?","answer":"

      As data volumes continue to grow, principles like functional dependencies will be crucial for the efficient management of this data. Machine learning algorithms for inferring functional dependencies from data can improve the performance and scalability of database management systems.<\/p>"},{"question":"How are Functional Dependencies related to Proxy Servers?","answer":"

      Functional dependencies can indirectly influence the functioning of proxy servers. Proxy servers often use databases to manage user data, access controls, and request logs. Therefore, optimizing database structures using functional dependencies can enhance the performance and data integrity of proxy services like OneProxy.<\/p>"}]},"_links":{"self":[{"href":"https:\/\/oneproxy.pro\/cn\/wp-json\/wp\/v2\/wiki\/477314","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/oneproxy.pro\/cn\/wp-json\/wp\/v2\/wiki"}],"about":[{"href":"https:\/\/oneproxy.pro\/cn\/wp-json\/wp\/v2\/types\/wiki"}],"version-history":[{"count":0,"href":"https:\/\/oneproxy.pro\/cn\/wp-json\/wp\/v2\/wiki\/477314\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/oneproxy.pro\/cn\/wp-json\/wp\/v2\/media\/477315"}],"wp:attachment":[{"href":"https:\/\/oneproxy.pro\/cn\/wp-json\/wp\/v2\/media?parent=477314"}],"curies":[{"name":"\u53ef\u6e7f\u6027\u7c89\u5242","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}