JAVA WEB 321Data Analysis and Design - Assignment 1 Frontsheet
-Advantages: +Structured independence is promoted +Users do not have to know the physical representation of the database +Use of SQL language to access data +Easier database design +Tabular view improves simplicity +Support large amounts of data +Data independence +Multi -level relationships between data sets +No need to predefined data relationships -Disadvantages: +Data anomalies +People need training if they want to use the system effectively and efficiently Network data model: In 1965 C.W. Bachman developed the first network data model to present complex data relationships more effectively than the hierarchical model. He tried to impose a database standard with his model and also wanted to improve database performance. It was in 1971 that the Conference on Data System Languages or CODASYL officially or formally defined the Network model. The network databases arrange its data as a directed graph and have a standard navigational language. -Advantages: +Multi-parent support +Somewhat same simplicity as the hierarchical model +Deals with even larger amounts of information than the hierarchical model +Promotes data integrity +Many to many relationship support +Data independence +Improved data access -Disadvantages: +Data relationships must be predefined +Much more complex than the hierarchical data model +User are still require to know the physical representation of the database +Information can be related in various an complicated ways +Lack structural Relationships: There are three kinds of relationships *One to one relationship: -One-to-one relationship is rare, b
Escuela, estudio y materia
- Institución
- Abby Kelley Foster Charter School
- Grado
- JAVA WEB 321
Información del documento
- Subido en
- 25 de julio de 2023
- Número de páginas
- 43
- Escrito en
- 2022/2023
- Tipo
- Examen
- Contiene
- Preguntas y respuestas
Temas
-
java web 321
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