Why Keyset pagination for performance in Rest API? - Purpose & Use Cases

The Big Idea

What if you could skip the slow flipping and jump straight to the next page instantly?

The Scenario

Imagine you have a huge list of products in an online store. You want to show 10 products per page to your users. If you try to get page 100 by counting all previous products each time, it feels like flipping through a giant book page by page.

The Problem

Using simple page numbers means the system must count and skip many items before showing the right page. This makes the server slow and can cause delays or errors when many users browse deep pages.

The Solution

Keyset pagination uses a 'bookmark' from the last item seen to quickly jump to the next set. It avoids counting all previous items, making the system faster and smoother for users.

Before vs After

✗ Before

SELECT * FROM products ORDER BY id LIMIT 10 OFFSET 990;

✓ After

SELECT * FROM products WHERE id > :last_seen_id ORDER BY id LIMIT 10;

What It Enables

It enables fast, reliable browsing through large lists without slowing down or crashing the server.

Real Life Example

When scrolling through social media feeds or product catalogs, keyset pagination helps load new items instantly without waiting for the whole list to be counted.

Key Takeaways

Manual page counting slows down with big data.

Keyset pagination uses a last seen marker for speed.

This improves user experience and server performance.