fourth normal form 英 [fɔːθ ˈnɔːml fɔːm] 美 [fɔːrθ ˈnɔːrml fɔːrm]网络 第四范式; 第四正规形式
Then ( R , Σ ) is said to be in Fourth Normal Form (4NF) if for every nontrivial multivalued dependency X Y implied by Σ , it holds that X is a superkey for R . Key Points In order to avoid update anomalies in database schemas containing functional and multivalued dependencies, ...
normal form factor 标准形数 prenex normal form 前束范式 characteristic normal form 特征正规形式 distinguished normal form 特异范式 相似单词 fourth 1. ordinal number 4th 第四 n. 1.(quarter) 四分之一 fourth class [ fourth-class ]的相关副词 Normal n. 标准,正常 a. 正常的,正规的,标准的...
fourth normal form 英文fourth normal form 中文【计】 第四范式
A relation R is in Fourth Normal Form (4NF) if and only if the following conditions are satisfied simultaneously: R is already in 3NF or BCNF. If it contains no multi-valued dependencies.
Fourth Normal Form (4NF) in database design refers to a level of organization that builds upon the principles of third normal form (3NF). It handles specific complex situations that may arise occasionally in relational databases, aiming to further optimize the design of relations. ...
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“This is part four of the series, The Five Normal Forms. Boyce-Codd Normal Form is abbreviated BCNF. It is also known as 3.5NF. 3.5 is 3½. It comes after the Third Normal Form. The Fourth Normal Form is abbreviated 4NF and comes after the Boyce-Codd Normal Form. The Fifth Normal...
目“盛I.oPM旧日‘.I,Ie和p删] 表达Boole函数一类特殊公式.区别为析取范式 (disjunctive normal form)(见B喊e函数的极小化(Boolean functio。5 mlnimization of))与合取范式(conzunctive noroial form).如果乘积x了,·x考的所有变元都不同,则称为人级匆等令零(elem“ntary conjunc-t,on),其中,当。