Index Management

Overview

Indexes are critical for MongoDB query performance. Sutido lets you view existing indexes, create new ones, and analyze index usage to optimize your database.

Viewing Indexes

Indexes appear in the tree explorer under each collection. You can also query indexes directly:

// List all indexes on a collection
db.users.getIndexes()

Index Types

Single Field Index

The most basic index type. Create on fields you frequently query:

// Create ascending index
db.users.createIndex({ email: 1 })

// Create descending index
db.users.createIndex({ createdAt: -1 })

Compound Index

Index multiple fields together. Order matters for query optimization:

// Good for queries on status, then sorting by date
db.orders.createIndex({ status: 1, createdAt: -1 })

Unique Index

Enforce uniqueness on a field:

db.users.createIndex({ email: 1 }, { unique: true })

Text Index

Enable full-text search:

db.articles.createIndex({ title: "text", content: "text" })

TTL Index

Automatically delete documents after a time period:

// Delete documents 30 days after createdAt
db.sessions.createIndex(
  { createdAt: 1 },
  { expireAfterSeconds: 2592000 }
)

Geospatial Index

For location-based queries:

db.places.createIndex({ location: "2dsphere" })

Analyzing Index Usage

Index Statistics

// Get usage statistics for all indexes
db.users.aggregate([{ $indexStats: {} }])

Explain Query Plan

See which index a query uses:

db.users.find({ email: "test@example.com" }).explain("executionStats")

Key Explain Fields

Field	What to Look For
winningPlan.stage	IXSCAN (good) vs COLLSCAN (bad)
totalDocsExamined	Should be close to nReturned
executionTimeMillis	Total query time
indexName	Which index was used

Creating Indexes

Basic Syntax

db.collection.createIndex(
  { field: 1 },           // Key pattern
  { option: value }       // Options
)

Common Options

Option	Description
unique	Enforce unique values
sparse	Only index documents with the field
background	Build in background (deprecated in 4.2+)
name	Custom index name
partialFilterExpression	Index only matching documents

Partial Index Example

// Only index active users
db.users.createIndex(
  { email: 1 },
  { partialFilterExpression: { status: "active" } }
)

Dropping Indexes

// Drop by name
db.users.dropIndex("email_1")

// Drop by key pattern
db.users.dropIndex({ email: 1 })

// Drop all indexes (except _id)
db.users.dropIndexes()

Index Best Practices

Index Selectively

Don't create indexes on every field. Focus on:

• Fields used in query filters
• Fields used for sorting
• Fields with high selectivity (many unique values)

Consider Write Performance

Every index slows down writes. Balance read performance gains against write overhead.

Monitor Index Size

// Check index sizes
db.users.stats().indexSizes

Remove Unused Indexes

Use $indexStats to find indexes that aren't being used and consider removing them.

Covered Queries

A query is "covered" when all requested fields are in the index. These are very fast:

// Index on { email: 1, name: 1 }
// This query is covered - no document fetch needed
db.users.find(
  { email: "test@example.com" },
  { name: 1, _id: 0 }
)

Next Steps

Customize Sutido in Settings & Config.