Architecture

Question 1

Single Tier architecture

Answer 1

• Database
• Client, server and database reside on same machine
• SQL queries

Question 2

Single Tier architecture rarely uses…

Answer 2

Security
Scalability
Resilience

Question 3

Two tier architecture

Answer 3

• Presentation layer
• Data stored on server separately
• ODCB (Open database connectivity)
• API allows client side program to call DBMS
• Added security to DBMS
• Not exposed to end user

Question 4

Three tier architecture

Answer 4

• Extension of two tier architecture
  1. Presentation Layer
  2. Application layer
  3. Database Server

Question 5

Three tier architecture how does it work?

Answer 5

• Application layer between the user and the DBMS
• communicates user requests to DBMS
• Send response from the DBMS to the user
• Processes functional Logic, constraint and rules
• Passes data to the user or down to the DBMS

Question 6

End Goal

Answer 6

• Separate user applications and physical database
• Support DBMS characteristics
• Program-data Independence
• Support of multiple views of the data

Question 7

Why is Three tier architecture good?

Answer 7

• Usually, the most popular database architecture
• Improved security (Data is kept separately from the server)
• Resilience (server might be broken into clusters to offer fail over)
• Scalability (Server can be load balanced and spread across number of servers providing more resilience)