DBMS

Question 1

What is DBMS?

Answer 1

A Database Management System (DBMS) is software designed to store, retrieve, define, and manage data in a database.

Question 2

What is RDBMS?

Answer 2

Relational DBMS

Question 3

Three-Tier Architecture of a DBMS

DBMS schemas at 3 levels:

Answer 3

• Internal schema at the internal level to describe physical storage structures and access paths. Typically uses a physical data model.
• Conceptual schema at the conceptual level to describe the structure and constraints for the whole database for a community of users. Uses a conceptual or an implementation data model.
• External schemas at the external level to describe the various user views. Usually uses the same data model as the conceptual level.

Question 4

What is a Database?

Answer 4

A database is an organized collection of structured information, or data, typically stored electronically in a computer system.

Question 5

6 Steps of Database Design process

Answer 5

1. Requirements Analysis
   
   • —What does the user want?
2. Conceptual Database Design
   —- Model Data requirements using a Conceptual Data
   Model –> ER model
3. Logical Database Design
   
   • — Model Data requirements using a Logical Data Model –> Relational Data Model
4. Schema Refinement
   - —Fine tune the result
5. Physical Database Design
   - —Implementation of the design using a Database Management System
6. Security Design
   
   • —Implement Controls to ensure security and integrity

Question 6

SQL?

Answer 6

– SQL stands for Structured Query Language.

– It is the language for storing, manipulating snd retrieving data in databases.

Question 7

Types of SQL Statements

Answer 7

1. Data Definition Language (DDL)
   CREATE, DROP, ALTER,…………………
2. Data Manipulation Language (DML)
   SELECT, INSERT, UPDATE, DELETE
3. Data Control Language (DCL)
   GRANT, REVOKE
4. Transaction Control Language (TCL)
   COMMIT, ROLLBACK,…………………..