MongoDB Query and Index Optimization

Query patterns and indexing strategies for MongoDB, maintained by MongoDB. Contains 46 rules across 5 categories, prioritized by impact. Includes MongoDB 8.0 features: bulkWrite command, $queryStats (introduced in MongoDB 6.0.7, with 8.1/8.2 enhancements), Query Settings, and updateOne sort option. Indexes are the primary tool for query performance—most slow queries are missing an appropriate index.

When to Apply

Reference these guidelines when:

• Writing new MongoDB queries or aggregations
• Creating or reviewing indexes for collections
• Debugging slow queries (COLLSCAN, high execution time)
• Reviewing explain() output
• Seeing Performance Advisor suggestions
• Optimizing aggregation pipelines
• Implementing built-in $text search with text indexes
• Adding geospatial queries
• Setting up TTL (time-to-live) for data expiration
• Analyzing index usage with $indexStats
• Profiling slow operations