翻訳と辞書 Words near each other ・ Canonical (company) ・ Canonical account ・ Canonical Acts ・ Canonical admonitions ・ Canonical age ・ Canonical analysis ・ Canonical basis ・ Canonical Book of the Tang Dynasty ・ Canonical bundle ・ Canonical commutation relation ・ Canonical connection ・ Canonical coordinates ・ Canonical coronation ・ Canonical correlation ・ Canonical correspondence analysis ・ Canonical cover ・ Canonical criticism ・ Canonical domain ・ Canonical election ・ Canonical ensemble ・ Canonical erection of a house of religious ・ Canonical faculties ・ Canonical form ・ Canonical hours ・ Canonical Huffman code ・ Canonical impediment ・ Canonical Inquisition ・ Canonical institution ・ Canonical link element ・ Canonical LR parser Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Canonical cover ： ウィキペディア英語版 Canonical cover A canonical cover $F\_c$ for F (a set of functional dependencies on a relation scheme) is a set of dependencies such that F logically implies all dependencies in $F\_c$, and $F\_c$ logically implies all dependencies in F. The set $F\_c$ has two important properties: # No functional dependency in $F\_c$ contains an extraneous attribute. # Each left side of a functional dependency in $F\_c$ is unique. That is, there are no two dependencies $a\; \backslash to\; b$ and $c\; \backslash to\; d$ in $F\_c$ such that $a\; =\; c$. == Algorithm for computing a canonical cover 〔''Database system concepts'' by Abraham Silberschatz et al〕== # $F\_c\; =\; F$ # Repeat: ## Use the union rule to replace any dependencies in $F\_c$ of the form $a\; \backslash to\; b$ and $a\; \backslash to\; d$ with $a\; \backslash to\; bd$ .. ## Find a functional dependency in $F\_c$ with an extraneous attribute and delete it from $F\_c$ # ... until $F\_c$ does not change 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Canonical cover」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.