Data Modeling Concepts and Comparison

The assignment content discusses three hierarchical data models: Hierarchical, Network, and Relational. The Hierarchical model stores data in a tree-like structure with one-to-many and one-to-one relationships. Its advantages include simplicity, security, and ease of addition/deletion, but it lacks structural independence. The Network model allows multiple parent-child nodes and supports many-to-many relationships, providing data independence and integrity. However, its complexity can be challenging to manage. The Relational model supports various relationships (one-to-one, one-to-many, many-to-many) and ensures data integrity by preventing anomalies when updating or deleting data. Its disadvantage is that once the database is created, it can be difficult to modify.

In hierarchical data model the data is stored in the form of tree in the database in
which there is root and all other nodes are the branches of the tree. The structure
of the same consist of one to many and one to one relationship, also it does not
provide data integrity because child node always depends on parent node for any
manipulation.
Advantage of this model is its simple structure, data security, the data stored in
this is integrated and efficient, data is easy to add and delete. Disadvantage of this
model is implementation complexity, managing database is a problem, lack of
structural independence,programming complexity, limitation in implementing.
In network model the data is stored in the form of multiple branches are
associated from the node and it seems to be multiple tree are there. It does
support many to many relation and the node can have multiple parent node as
well as multiple child node.
The advantage of network model is easy to access its data, it can handle more
relationship type, data independence, data integrity. The disadvantage of this
model is its system complexity, lack of structural independence and its procedural
access language.
Relation model consist of relation between the table and their nodes. It does
support all relation like one to many, many to many and one to one and it free
from any anomalies like update or delete of node and if we delete a node it does
not affect on other.
The advantage of relation model is its ability to link information about a particular
person who is in several database together by simple links. The disadvantage of
this model is that once the database is created it is not change easily so any
database forming as part of relation database must be very careful planned.