Definition are Network, Hierarchical and entity -relationship model
Definition are Network, Hierarchical and entity -relationship model Network Model:- The network Model data are represented by collection of records and relationships among data are represented by links. Advantages of network Model:- Simplicity:- The network Model is also conceptually simple and easy to design. Ability to handle more relationship type:- The network Model can handle the one to many and many to many relationships. Easy of data access:- Relationship is a set comprises of two type of records an owner record and a member record. Data integrity:- In a network model no member can exist without an owner. A user must therefore first define the owner record and then the member record. Data independence:- The network Model draws a clear line of demarcation between the programs and the complex physical storage details. Database standard:- The standard devised by the DBTG (database Task Group of CODASYL Commtiee)form the basis of the network Model....