Database Management system DBMS

1. Netaji Subhash
Engineering College
Name- Debaditya Ghosh
University Roll- 10900121235
Registration Number- 211090100120032
Subject name- Database management system(DBMS)

2. What is DBMS ?
It is a software that works with operating system to
• Create Request
• Process
• Store Response Retrieve
• Retrieve
• Control
and manage the data. It acts as the interface between the application program and the
database.
Application
program Database
DBMS

3. Advantages of DBMS over Filesystem
• No data redundancy and inconsistency .
• No data isolation.
• Easy and smooth access of data from the database.
• Data Integrity
• Atomicity
• Allows concurrent access.
• Very secure.
• Robust

4. Define 3 Level Architecture of DBMS
Block diagram of 3 level architecture:-
View / Conceptual Level
Logical Level
Physical Level

5. Define 3 Level Architecture of DBMS(cont.)
• Physical / Internal level – This level actually describes the physical storage of data which
is stored in encrypted form in the memory. So, in the physical level database is not stored as
the tabular form. It gives the complete details of data storage, access paths, different record
types and sequence of records etc.
• Logical Level- This level describes the overall logical structure of whole database for a
community of users. This level is relational because data visible in this level will be relational
tables. It is defined to hide the actual physical storage and concentrate on relational model
of the database.
• View / External Level- It is concerned with the individual or end users . This layer
describes the actual view of the data seen by the individual users i.e. how the users will see
the data or how the data is going to be presented in front of the users.