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