Page 2 - Relational Databases

They create access profiles for users and apply limitations to maintain isolation and force
security.
Designers − Designers are the group of people who actually work on the designing part of
the database. They keep a close watch on what data should be kept and in what format.
They identify and design the whole set of entities, relations, constraints, and views.
End Users − End users are those who actually reap the benefits of having a DBMS. End users
can range from simple viewers who pay attention to the logs or market rates to
sophisticated users such as business analysts.

Advantages of DBMS
 Elimination of Data Redundancy
 Sharing of Data
 Data Consistency is maintained
 Data Independence is maintained
 Reduced Programming Effort
 Improved Data Integrity
 Data Security
 Data Privacy
 Backup and Recovery Procedures
 Economical
 DBMS gives faster access to data

Data Models
Data model defines how data is connected and how data is processed and stored inside the
system. They organize data for various users.
Importance:
 Gives an overall view of the database.
 Organize data for various users.
 They are a communication tool.
 Data models are used to implement abstraction in a DBMS.

Data Models Used by DBMSs
Main data models used by most of the DBMS are as follows:
 Network Data Model
 Hierarchical Data Model
 Relational Data Model
 Object-Oriented Data Model

Relational Data Model
Basic Structure
 Implemented through Relational DBMS (RDBMS)
 RDBMS manages the complexity of physical implementation
 RDBMS represents the database as a collection of relations.
 A relation is nothing but a table of values.