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Relational Data Model
This data model is based on the principle of setting relationships between two or more tables of the same database.
It is the most used database model. The relational database model was proposed by Edgar F. Codd in 1970. Relational
database model is the most common type of database model. In the relational database model, data is organised
into tables, with each table consisting of rows and columns. Each row represents a record or entity, and each column
represents a specific attribute or field of that entity. The data in different tables are related with common fields. So,
relations are set between tables based on common fields. That is why this model is termed as relational database
model. These relationships enable the database to maintain data integrity and enforce constraints such as referential
integrity.
By storing related data in separate tables and establishing relationships between them, the relational model allows for
efficient data organisation, retrieval, and manipulation. This model’s flexibility and scalability make it one of the most
widely used and versatile database models in various industries and applications.
The difference among hierarchical, network, and relational data models is shown in the following table:
S. No. Hierarchical Data Model Network Data Model Relational Data Model
1 Data is organised in a tree-like Like the hierarchical model but Data is represented in tables
structure, with parent-child with more flexible relationships. consisting of rows and columns.
relationships.
2 Each child node has exactly Nodes can have multiple parent It’s based on mathematical set
one parent node. nodes, allowing for more complex theory and predicate logic.
connections.
3 It’s primarily used in older It uses pointers to represent Relationships between tables are
database systems. relationships between records. established using keys, primarily
primary and foreign keys.
4 It is rigid in structure and is not Developed as an improvement over Offers flexibility and scalability,
suitable for applications with the hierarchical model but still has making it widely adopted in modern
evolving data structures or limitations in terms of complexity database systems.
complex relationships. and scalability.
5 Querying hierarchical data can Querying in the network data Querying is simplified with SQL
be complex due to its rigid model can be more complex (Structured Query Language) which
structure. compared to the relational model. provides a standardised way to
retrieve and manipulate data.
RELATIONAL DATABASE MANAGEMENT SYSTEM (RDBMS)
RDBMS is an advanced form of Database Management System and is based on a Relational Model. In this model, a
relational database has a set of related tables that are interlinked to each other based on a common field. It is a very
efficient way of representing data and allows data in a table to be represented in a two-dimensional form and is known
as a Relation. A row in a relation is called Tuple or Record. It is a collection of related data fields. Each tuple uniquely
identifies a record based on a unique key-known as Primary key. Data from different relations can be easily extracted
as they are interlinked based on a Primary key. A column in a relation is called an Attribute or Field. It store similar
data type value.
Structured Query Language (SQL) is the standard language for managing relational databases and performing various
operations on the data in the tables. It would enable us to store, retrieve, and manipulate data in the tables.
Database Management System using LibreOffice Base 297

