层次数据模型、网络数据模型和关系数据模型之间有什么区别？

Question

请告诉我分层数据模型、网络数据模型和关系数据模型之间的区别是什么？

Answer 1

分层模型

1.One to many or one to one relationships.
2.Based on parent child relationship.
3.Retrieve algorithms are complex and asymmetric
4.Data Redundancy more

网络模型

1.Many to many relationships.
2.Many parents as well as many children.
3.Retrieve algorithms are complex and symmetric
4.Data Redundancy more

关系模型

1.One to One,One to many, Many to many relationships.
2.Based on relational data structures.
3.Retrieve algorithms are simple and symmetric
4.Data Redundancy less