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DBMS Data Models: Architecture and Drawbacks
In this tutorial, we will learn about the architecture of data models and the drawbacks of the different types of data models in database management system (DBMS).
By Bharti Parmar Last updated : May 26, 2023
Prerequisites: Data Models and Their Types
Architecture of Data Model
The following images depict the architecture of DBMS data model:
Physical data organization
Hierarchical Data Model
This model is like a hierarchical tree that means tree structure is used to construct a hierarchy of records in form of node and branches; first introduced (IMS) information management system in the 1960's.
Drawbacks of Hierarchical Model
- A hierarchical model is not enough to present all the data between the data element.
- It cannot demonstrate the overall data model for the enterprise because of the non-availability of actual data at the time of designing the data model.
- It cannot follow many to one and many to many relations.
Network Data Model
This model based on graph data structure proposed by IBM in 1969. It is an improvement of the hierarchical model.
Drawbacks of Network Model
- Its complexity is the main drawback because all records are maintained by using pointers so, whole database structure becomes very complex.
- A transaction is maintained using the pointer and tracing the pointer is the drawback of its design.
- The relation between data element must be re-stabilized. We cannot stabilize relationship as per need requirement during their uses.
- Structure changes to the database are very difficult.
Relational Data Model
In 1970's Dr. EF-Codd (Edgar F. Codd) working as a mathematician in IBM proposed a simple data model which is based on table and relation. A relation is a 2D array or matrix-like structure. He proposed 12 rules of which are known as golden rules of EF-Codd. Any DBMS follow all the 12 rules is known as complete RDBMS. There is no DBMS in the world follow all the 12 rules maximum 11.5 rules have been followed by present RDBMS. If any DBMS follow less than 11.5 rules called partial RDBMS. Microsoft SQL Server 2008 is a popular example of RDBMS.
Drawbacks of Relational Data Model
RDBMS used an object-oriented programming language like java. So, there is a limitation of the language.
Conclusion
In this tutorial, we have learned the drawbacks of hierarchical, network and relational data model and Architecture of data model. In the next article, we will discuss the 12 golden rules of EF-Codd. Stay tuned for the next article. Have a nice day! Happy Learning!