Data Model Overview
Data
Data is defined as the collection of information and a database is referred to as a collection of related data.
Model
A database model shows the logical structure of a database, including the relationships and constraints that determine how data can be stored and accessed.
Data Model
The “data model” refers to the way data is organized, documented, and defined within a database. The data model definition also describes the elements used to standardize the system, such as associations, entities, and requirements.
It is basically classified into 3 types:
Conceptual Data Model
A conceptual data model identifies the entities that describe the data and relationships between them. Conceptual data models only show the highest-level relationships between entities, not attributes or primary keys within the data model.
Physical Data Model
A physical data model identifies the table structures that will be built in the database, including all tables, columns, primary keys, and foreign keys used to identify the relationships between tables.
Relational Data Model
A relational data model is the basis for SQL databases. Relational data models have a fixed schema and deal with structured data. In a relational database management system, or RDBMS, the database is the outermost container that has data associated with an application.
Some Other Data Models
Hierarchical Model
The Hierarchical Model was the first database management system model. The hierarchical Model is one of the oldest models in the data model which was developed by IBM in the 1950s. The data is organized into a tree-like structure where each record consists of one parent record and many children.
Network Model
The Network Model was formalized by the Database Task group in the 1960s. This model is the generalization of the hierarchical model.
Object-Oriented Data Model
In the Object-Oriented Data Model, data and their relationships are contained in a single structure which is referred to as an object in this data model. In this, real-world problems are represented as objects with different attributes.
Advantages of Data Models
- Data Models help us in representing data accurately.
- It helps us in finding the missing data and also in minimizing Data Redundancy.
- Data Model provides data security in a better way.
- The data model should be detailed enough to be used for building the physical database.
- The information in the data model can be used for defining the relationship between tables, primary and foreign keys, and stored procedures.
Disadvantages of Data Models
- In the case of a vast database, sometimes it becomes difficult to understand the data model.
- You must have the proper knowledge of SQL to use physical models.
- Even smaller changes made in structure require modification in the entire application.
- There is no set data manipulation language in DBMS.
- To develop a Data model one should know physical data stored characteristics.