Data Models in DBMS:
In this article, I am going to discuss Data Models in DBMS. Please read our previous article where we discussed Database Management Terminology. At the end of this article, you will understand the following pointers.
- What are Data Models in DBMS?
- Hierarchical Data Model
- Advantages and Disadvantages of Hierarchical Data Model
- Network Data Model
- Advantages and Disadvantages of Network Data Model
- Relational Data Model
- Advantages and Disadvantages of Relational Data Model
What are Data Models in DBMS?
A set of rules and standards that define how the database organizes/stores data is called a database model. It is also defining how users view the organization of data.
- Hierarchical Model
- Network Model
- Relation model
Hierarchical Data Model in DBMS:
The hierarchical model arranges records in the hierarchy like an organizational chart each record type in this model is called a node or segment. A node represents a particular entity, the top-most node is called root each node is a subordinate of the node that is at the next higher level.
A higher-level node is called a parent and the lower-level node is called the child. A parent node can have one or many child nodes. A child node can have only one parent node. This kind of structure is often called an inverted tree.
Advantages of Hierarchical Data Model:
- Efficient storage for data that have a clear hierarchy.
- Parent/Child relationship promotes conceptual simplicity & data integrity.
- It is efficient with 1:M relationships.
- It promotes data sharing.
- It is easy to understand and use.
Disadvantages of Hierarchical Data Model:
- It is difficult to modify.
- It cannot represent all the relations between data.
- It is a restricted model
Network Data Model in DBMS:
The network model is similar to the hierarchical model only the difference is that child can have more than one parent node. The child nodes are represented by arrows in the network model it also provides more flexibility than the hierarchical model.
Advantages of Network Data Model:
- It represents complex data relationships better than hierarchical models.
- It handles more relationship types, such as M:N and multi-parent.
- Data access is more flexible than the hierarchical model.
- Improved database performance.
- It includes DDL and DML.
Disadvantages of Network Data Model:
- It is slow, complex, and more difficult to maintain.
- It requires a more complex diagram to represent a database.
Relational Data Model in DBMS:
The relation model is the most commonly used database model it is more flexible than hierarchical and network database models. The relational model consists of simple relations a relation is a term used for the table. A relation represents a particular entity it is used to store information about the entity the relationships are based on the data of the entities. Dr. E.F Codd introduced the relational model.
The table also called relation,
Advantages of Relational Data Model:
- Changes in a table’s structure do not affect data access or application program.
- Tabular view substantially improves conceptual simplicity, thereby promoting easier database design, implementation, management, and use.
- Have referential integrity controls ensure data consistency.
- RDBMS isolates the end-users from physical level details and improves implementation and management simplicity.
Disadvantages of Relational Data Model:
- Conceptual simplicity gives relatively untrained people the tools to use a good system poorly.
- It may promote islands of information problems as individuals and departments can easily develop their own applications.
In the next article, I am going to discuss Introduction to RDMB (Relational Database Management System). Here, in this article, I try to explain Data Models in DBMS and I hope you enjoy this Data model in DBMS article.