When should you use MongoDB over SQL?

What You'll Learn

• Use cases for MongoDB
• Use cases for SQL
• Decision factors

Use MongoDB When

• Flexible/evolving schema - Requirements change frequently
• Hierarchical data - Nested documents, JSON-like data
• High write loads - Logging, IoT, real-time analytics
• Horizontal scaling - Need to distribute data across servers
• Rapid prototyping - Quick development cycles

Use SQL When

• Complex relationships - Many-to-many relationships
• ACID transactions - Financial, banking systems
• Complex queries - Multi-table joins
• Data integrity - Strict schema requirements
• Reporting - Complex aggregations

Comparison

// MongoDB - Embedded document
{
  _id: 1,
  name: "John",
  orders: [
    { product: "Laptop", price: 999 },
    { product: "Mouse", price: 29 }
  ]
}

// SQL - Separate tables with foreign keys
// users table: id, name
// orders table: id, user_id, product, price

Decision Matrix