Sorting, Limiting, and Pagination

Retrieving data efficiently matters just as much as retrieving it correctly. This lesson covers sort(), limit(), and skip() — the trio that powers ordered results and pagination in MongoDB.

1. Sorting Results

// Sort ascending (1) by price
db.products.find().sort({ price: 1 })

// Sort descending (-1) by price
db.products.find().sort({ price: -1 })

// Sort by multiple fields
db.products.find().sort({ category: 1, price: -1 })

2. Limiting Results

// Return only the first 10 documents
db.products.find().limit(10)

// Combine sort and limit — top 5 most expensive products
db.products.find().sort({ price: -1 }).limit(5)

3. Skipping Results

// Skip the first 20 documents
db.products.find().skip(20)

// Pagination: page 3, 10 results per page
db.products.find().sort({ _id: 1 }).skip(20).limit(10)

4. Cursor-Based (Range) Pagination

Instead of skipping N documents, filter using the last seen _id — far more efficient at scale.

// First page
db.products.find().sort({ _id: 1 }).limit(10)

// Next page: use the last _id from the previous page
db.products.find({ _id: { $gt: lastSeenId } }).sort({ _id: 1 }).limit(10)

5. Sorting on Indexed Fields

Sorting is far more efficient when the sort field is indexed, since MongoDB can retrieve documents already in order instead of sorting them in memory.

db.products.createIndex({ price: -1 })
db.products.find().sort({ price: -1 })  // Uses the index — no in-memory sort

6. Pagination Checklist

• ✅ Understand sort(), limit(), and skip() individually
• ✅ Combine them correctly for classic offset pagination
• ✅ Know skip()'s performance cost on large datasets
• ✅ Implement cursor-based pagination for scale
• ✅ Index fields used for sorting