Page 212 - IT_V1.0_Class10
P. 212
By storing related data in separate tables and linking them through common fields, the relational model
ensures efficient data organisation, retrieval, and manipulation. This model’s flexibility and scalability make
it one of the most prevalent and versatile database models, used across various industries and applications.
The difference among hierarchical, network and relational data models is shown in the following table:
Feature Hierarchical Data Model Network Data Model Relational Data Model
Structure Tree-like structure with Similar to the hierarchical Table-based structure
parent-child nodes model but with more with rows and columns
flexible relationships.
Data Records linked by Records linked by multiple Data stored in tables
Representation hierarchical paths paths
Parent-Child Each child has only one Each child can have Relationships established
Relationship parent multiple parents via common fields
Flexibility Less flexible, rigid structure More flexible, complex Highly flexible, easy to
structure modify
Data Integrity Enforced through hierarchy Maintained through Enforced through
complex relationships constraints and keys
ELEMENTS OF DATABASE
Data in a DBMS is generally kept in a tabular format and is organised by fields, records and files. A field
represents a single type of related information; a record is a complete set of values stored under fields,
whereas a file is a collection of records.
Table: Tables are the basic structure of a database where data is stored. Each table consists of rows and
columns. A table is a collection of logically related records.
Generally, a column represents a field that contains information of a particular type, whereas a row
represents records that contain information of the related fields.
Columns/Fields/Attributes: A column is a set of data values of a particular simple type, one for each row
of the table. For example, age, name, address, designation and phone are fields in the given table.
Records/Rows/Tuples: A record, also known as a row or tuple, is a collection of multiple data values
stored in related fields that can be treated as a single unit. Each row represents a single data item in
a table.
For example, 22, Aryan, New Market Lane, Accountant, 990845XXXX is one of the records of the table
given below:
Fields
Age Name Address Designation Phone
22 Aryan New Market Lane Accountant 990845XXXX
Table
50 Lucky H.B. Road Clerk 995525XXXX Records
27 Rohit New Fashion Street Cashier 986545XXXX
210 Information Technology Play (Ver 1.0)-X

