- Trending Categories
Data Structure
Networking
RDBMS
Operating System
Java
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Explain the three level schema architecture in DBMS?
The three-schema architecture divides the database into three-level used to create a separation between the physical database and the user application. In simple terms, this architecture hides the details of physical storage from the user.
The database administrator (DBA) responsible is to change the structure of database storage without affecting the user’s view. It deals with the data, the relationship between them and the different access methods implemented on the database. The logical design of database is called a schema
This architecture contains three layers of database management system, which are as follows −
External level
Conceptual level
Internal level
External/ View level
This is the highest level of database abstraction. It includes a number of external schemas or user views. This level provides different views of the same database for a specific user or a group of users. An external view provides a powerful and flexible security mechanism by hiding the parts of the database from a particular user.
Conceptual or Logical level
This level describes the structure of the whole database. It acts as a middle layer between the physical storage and user view. It explains what data to be stored in the database, what the data types are, and what relationship exists among those data. There is only one conceptual schema per database.
This level describes the structure of the whole database. It acts as a middle layer between the physical storage and user view. It explains what data to be stored in the database, what the data types are, and what relationship exists among those data. There is only one conceptual schema per database.
Internal or Physical level
This is the lowest level of database abstraction. It describes how the data is stored in the database and provides the methods to access data from the database. It allows viewing the physical representation of the database on the computer system.
The interface between the conceptual and internal schema identifies how an element in the conceptual schema is stored and how it may be accessed. It is one which is closest to physical storage. The internal schema not only defines different stored record types, but also specifies what indices exist, how stored fields are represented.
The three level schema architecture in DBMS is given below −
- Related Questions & Answers
- Three Level Architecture of Database
- Explain the architecture of DBMS?
- Explain the concept of DBMS schema with examples?
- What is instance and schema (DBMS)?
- Explain the ODBC architecture?
- Discuss the Single Level Interrupts in Computer Architecture?
- Explain the characteristics of DBMS?
- Explain the components of DBMS?
- Explain the architecture of JDBC?
- Explain the logical operators in DBMS
- Explain the Network Model in DBMS?
- Explain the Relational Model in DBMS?
- Explain the cardinality concept in DBMS?
- Explain the relational algebra in DBMS?
- Explain the stream architecture in .NET