Chapter one Flashcards
(10 cards)
Q: What is a database?
A: A collection of organized data stored electronically, designed to manage and retrieve information efficiently.
Q: What is the role of a Database Management System (DBMS)?
Manages and controls access to the database.
Provides security, backup, and recovery.
Allows multi-user access.
Q: What are the differences between a file-based system and a database system?
File-Based: Data stored in separate files, prone to redundancy and inconsistency, less secure.
Database: Centralized storage, reduces redundancy, improves security and consistency.
Q: What are the three levels of DBMS architecture?
Internal Schema: Physical storage details.
Conceptual Schema: Logical structure of the database.
External Schema: User-specific views.
Q: What are the three types of database constraints?
Domain Constraints: Restrict values in a column (e.g., age must be 18–60).
Key Constraints: Ensure each row is unique (e.g., Primary Key).
Referential Integrity: Ensures foreign key values match primary key values.
Q: What is the difference between data and information?
Data: Raw, unprocessed facts (e.g., 20, John).
Information: Processed data that is meaningful (e.g., “John is 20 years old”).
: What is the role of a Database Administrator (DBA)?
A: Manages the database, controls user access, creates backups, and monitors performance.
Q: Name the four types of database languages.
DDL (Data Definition Language): Defines database structure (e.g., CREATE, DROP).
DML (Data Manipulation Language): Manipulates data (e.g., SELECT, INSERT, UPDATE).
DCL (Data Control Language): Manages permissions (e.g., GRANT, REVOKE).
TCL (Transaction Control Language): Manages transactions (e.g., COMMIT, ROLLBACK).
Q: What is a primary key, and why is it important?
A: A unique identifier for each row in a table, ensuring no two rows are identical.
Q: What is a foreign key, and how does it work?
A: A column in one table that links to the primary key of another table, maintaining relationships between tables.
