Database normalization vs denormalization in HLD - Architecture Patterns Compared

System Overview - Database normalization vs denormalization

This system explains the difference between database normalization and denormalization. Normalization organizes data to reduce duplication and improve consistency. Denormalization combines data to speed up read operations at the cost of some duplication.

Key requirements include balancing data integrity, query speed, and storage efficiency depending on the use case.

Architecture Diagram

User
  |
  v
Load Balancer
  |
  v
API Gateway
  |
  +-------------------+
  |                   |
Cache (Normalized)   Cache (Denormalized)
  |                   |
Normalized DB      Denormalized DB
  |                   |
Response            Response

Components

User

user

Initiates requests to the system

Load Balancer

load_balancer

Distributes incoming requests evenly to API Gateway

API Gateway

api_gateway

Routes requests to either normalized or denormalized database services

Normalized DB

database

Stores data in normalized form to reduce duplication and maintain integrity

Denormalized DB

database

Stores data in denormalized form to optimize read performance

Cache (Normalized)

cache

Caches frequently accessed normalized data to reduce DB load

Cache (Denormalized)

cache

Caches frequently accessed denormalized data for faster reads

Response

response

Sends processed data back to the user

Request Flow - 8 Hops

User → Load Balancer

Load Balancer → API Gateway

API Gateway → Cache (Normalized or Denormalized)

Cache (Normalized or Denormalized) → API Gateway

API Gateway → Normalized DB or Denormalized DB

Normalized DB or Denormalized DB → API Gateway

API Gateway → Cache (Normalized or Denormalized)

API Gateway → Response

Failure Scenario

Component Fails:Cache (Normalized or Denormalized)

Impact:Cache misses increase, causing more direct database queries and higher latency

Mitigation:System falls back to database queries; cache is rebuilt over time; consider cache replication or failover

Architecture Quiz - 3 Questions

Which component reduces database load by storing frequently accessed data?

A Load Balancer

B Cache

C API Gateway

D User

Design Principle

This architecture demonstrates the trade-off between normalization and denormalization in databases. Normalization ensures data integrity and reduces duplication, while denormalization improves read speed by storing combined data. Caches are used to optimize performance by reducing database load. The system routes requests through load balancers and API gateways to maintain scalability and control.