Index one frequently filtered field.
Section: Create indexes
Create a single-field index
javascript
javascript
db.users.createIndex({ email: 1 })Explanation
A single-field index is often the first optimization for lookup-heavy fields.
Learn the surrounding workflow
Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.
Related commands
Same sheet · prioritizing Create indexes
Create a compound index
Index fields used together in filters or sorts.
Enforce uniqueness with an index
Prevent duplicate values at write time.
Force a specific index with hint
Test how a query behaves with a chosen index.