Create a single-field index
Index one frequently filtered field.
javascriptANYmongodbindexcreateIndex
javascript
db.users.createIndex({ email: 1 })Notes
A single-field index is often the first optimization for lookup-heavy fields.
MongoDB Indexes, Explain Plans, and Performance
Create indexes, inspect query plans, and troubleshoot common MongoDB query performance issues.
Export
Copy the compact sheet, download it, or print it.
Download
`D` dense toggle · `C` copy all
Create indexes
The most common index patterns for apps and APIs.
Create a compound index
Index fields used together in filters or sorts.
javascriptANYmongodbindexcompound
javascript
db.orders.createIndex({ status: 1, created_at: -1 })Notes
Compound indexes are useful when queries filter and sort on a predictable pattern.
Enforce uniqueness with an index
Prevent duplicate values at write time.
javascriptANYmongodbindexunique
javascript
db.users.createIndex({ email: 1 }, { unique: true })Notes
Great for usernames, emails, external ids, and other unique keys.
javascript
db.articles.createIndex({ title: "text", body: "text" })Notes
Text indexes support MongoDB text search syntax over indexed fields.
javascript
db.users.getIndexes()Notes
Useful before adding more indexes or debugging an execution plan.
Explain and tune
See what the query planner is doing and validate index usage.
Explain a query
Show the execution plan for a `find()` query.
javascriptANYmongodbexplainperformance
javascript
db.orders.find({ status: "paid" }).sort({ created_at: -1 }).explain("executionStats")Notes
`executionStats` gives practical detail such as scanned docs, scanned keys, and returned docs.
Force a specific index with hint
Test how a query behaves with a chosen index.
javascriptANYmongodbhintindexes
javascript
db.orders.find({ status: "paid" }).hint({ status: 1, created_at: -1 })Notes
Helpful for diagnostics, but avoid overusing hints in app code unless there is a strong reason.
Hide an index for testing
Temporarily hide an index from the planner.
javascriptANYmongodbhideIndexindexes
javascript
db.orders.hideIndex({ status: 1, created_at: -1 })Notes
Hidden indexes can help you test whether an index is still needed before dropping it.
Inspect collection stats
View storage and index metrics for a collection.
javascriptANYmongodbcollStatsstats
javascript
db.runCommand({ collStats: "orders" })Notes
Useful for checking total size, avg document size, and index footprint.
javascript
db.orders.dropIndex({ status: 1, created_at: -1 })Notes
Every index speeds some reads but adds write and storage cost, so removing unused ones can help.
More in MongoDB
MongoDB Transactions and Change Streams
Use sessions, multi-document transactions, and change streams for modern event-driven and consistency-sensitive MongoDB applications.
MongoDB Backup, Restore, and Replica Set Workflows
Use mongodump, mongorestore, replica set commands, and diagnostic tools for operational MongoDB workflows.
MongoDB Import, Export, and Database Tools
Use mongoimport, mongoexport, bsondump, and GridFS tools for practical MongoDB data movement workflows.
MongoDB Users, Roles, and Administrative Commands
Create users, grant roles, inspect server status, and run the most common administrative commands in MongoDB.
MongoDB Aggregation Pipeline Patterns
Group, project, sort, unwind, lookup, facet, and aggregate analytics data with MongoDB pipelines.
MongoDB Update Operators and Array Patterns
Use $set, $unset, $inc, $push, $addToSet, positional updates, and arrayFilters for real-world MongoDB mutations.