bcnf

Research on the Prime Attribute Problem of the Relation Scheme in BCNF

属于BCNF的关系模式主属性问题研究

The New Method for Decomposing a Relation Scheme into BCNF

关系模式的BCNF分解的一种新方法

Applications of Closure Algorithm for Relation Decomposition Based on BCNF

闭包算法在基于BCNF的关系分解中的应用

Research on the Problems of Candidate Keys of the Relation Scheme in BCNF

属于BCNF的关系模式候选关键字问题研究

The Separate Algorithm of Improved BCNF Based on Inverse Hypergraph

基于逆向超图的改进的BCNF的分解算法

A polynomial time algorithm to decide BCNF

一个BCNF的多项式时间判定算法

Decompositions for Relational Schema Under Null Value Circumstances Into BCNF With Lossless Joins

空值环境下关系模式到（N）BCNF无损连接分解

Finally , we presented Boyce-Codd normal form ( BCNF ) and discussed how it is a stronger form of3NF .

最后，我们提出了博伊斯-科德范式（BCNF），并讨论如何，它是一个更强的3NF形式。

The mistake in the proving process of the problem of deciding BCNF in reference is pointed out , and a polynomial time algorithm to decide whether a relation schema is in BCNF is given .

文中指出了文献〔1〕中对BCNF判定问题证明过程的错误之处，通过分析属于BCNF的关系模式的结构特点，给出了一个判定关系模式是否属于BCNF的多项式时间算法。

The decomposition of a database schema to meet preserving functional dependency , lossless join , BCNF and no - α ring is one of the important problems of the theoretical research of a database and its application .

一个数据库模式分解为满足保持函数依赖、无损联接性、BCNF且无α环是数据库理论和应用研究的重要问题之一。

The traditional algorithm for decomposing a relation scheme into BCNF with a lossless join must determine whether a relation scheme is in BCNF . Unfortunately , it has been proved that the determination is NP-complete .

传统的关系模式的BCNF分解算法必须判断一个关系模式是否为BCNF，该判断是一个NP-完全问题，因此传统算法缺乏实用性。

In the phase of detailed design , it uses class diagram and timing diagram to describe functions of the system , and fully considers the relationship between various data tables of the database to draw a consistent BCNF database design .

对于详细设计的时候根据功能类图和时序图，对于系统所要实现的功能进行了描述，在数据库设计的时候充分考虑数据库的各个数据表格之间的关系，得出一个比较符合BCNF的数据库设计。

This paper introduces the theory of Normal Form in Database designing of Relation Mode , and proposes that resorting to BCNF & 3NF to design the structure of Table in Library Network Database having the optimized performance , which can process huge data with high speed .

本文介绍了关系模型数据库设计的范式理论，并结合高校图书馆网络数据库的性能优化问题，提出利用BCNF和第三范式设计表结构，使得该数据库能高速处理大容量的数据。

On this basis , it discusses its scheme decomposition and concludes that when D has weak conflict , the decomposition meeting join-lossless , FD and BCNF is α - cyclic , laying the foundation for further investigation of α - acyclic decomposition .

在此基础上讨论了它的模式分解问题，给出了在D有弱冲突时满足无损连接、保FD、BCNF的分解是有α环的结论，为进一步研究无α环的分解奠定了基础。