Common Pitfalls with Indexes

MongoDB Indexing Mistakes to Avoid

Indexes speed up queries, but can backfire if used wrong

By Sharanmeet Singh••
Tags:MongoDBIndexingPerformance

MongoDB Query Generator

Generate MongoDB queries and aggregation pipelines

Try Generator

MongoDB Indexing Mistakes

Indexes are powerful but can cause performance issues if misused.

Common Mistakes

  1. Too many indexes → Slows down writes
  2. Unused indexes → Wastes memory
  3. Wrong index order → Breaks query optimization

Example of Good Index

{
  "status": 1, "createdAt": -1
}

Supports queries like:

{ "status": "active" }

Pro Tips

  • Use explain() to analyze queries
  • Drop unused indexes
  • Always index fields used in $lookup or $sort