5. Indexing and Query Optimization for Performance 🚀

Intermediate

Efficient querying is vital for scalable applications. MongoDB supports various index types, including single-field, compound, multi-key, text, and geospatial indexes.

Creating Indexes:

// Single-field index
db.users.createIndex({ name: 1 }) // ascending

// Compound index
db.users.createIndex({ name: 1, age: -1 }) // descending

Query Optimization:

  • Use projections to return only necessary fields
  • Analyze query plans with explain():
db.users.find({ age: { $gt: 20 } }).explain()
  • Regularly review index usage and remove unused indexes to optimize performance.

Proper indexing reduces query response times significantly, especially with large datasets, and is crucial for maintaining application responsiveness.