• ETRI Journal
• /
• v.9 no.3
• /
• pp.43-54
• /
• 1987

주어진 릴레이션 스킴(relation scheme)을 이에 관련된 함수적 종속(functional dependency)들을 가지고 분해하여 Boyce-Codd 정규형(Boyce-Codd normal form)에 속하는 릴레이션 스키머(schema)로 정규화(normalization)시키는 기존의 분해 알고리즘(decomposition algorithm)은 구현해서 사용하기에 적합하지 못하다. 본 고에서는 기존의 알고리즘 구현시 발생하는 문제점을 분석하고 이런 문제점을 해결하는 방법을 제시하며, 이를 토대로 Boyce-Codd 정규형 릴레이션 스킴을 생성하는 새로운 알고리즘을 제시하고, 이 알고리즘을 UNIX 환경하에 C 언어로 구현한 후 임의의 자료를 수행하여 얻어진 릴레이션 스키머와 기존의 알고리즘에 의해 얻어진 릴레이션 스키머를 비교분석하였다.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.13 no.1
• /
• pp.51-64
• /
• 1988

A new approach to the logical design of 4NF database shceme, which can be easily automated, is proposed. The main features of the approach are : introduction of a single attribute right hand side, extension of the concept of independent relations, semantic analysis, and adaoption of dependency matrix. The underlying viewpoints of functional relationships of the approach are different from Fagin's in that we distinguish functional and multivalued dependency in terms of cardinality. An algorithm for automatic generation of fourth normal form is presented and implemented.

• Journal of Korean Institute of Industrial Engineers
• /
• v.37 no.3
• /
• pp.264-270
• /
• 2011

A new method for creating a logical data model is proposed. The logical data model developed by the method defines table, primary key, foreign key, and fields. The framework of the logical data model is constructed by modeling the relationships between events and their related entity types. The proposed method consists of a series of objective and quantitative decisions such as maximum cardinality of relationships and functional dependency between the primary key and attributes. Even beginners to database design can use the methology as long as they understand such basic concepts about relational databases as primary key, foreign key, relationship cardinality, parent-child relationship, and functional dependency. The simple and systematic approach minimizes decision errors made by a database designer. In practial database design the method creates a logical data model in Boyce-Codd normal form unless the user of the method makes a critical decision error, which is very unlikely.