Keyset pagination for performance in Rest API - Mini Project: Build & Apply

Keyset Pagination for Performance in REST API

📖 Scenario: You are building a REST API that returns a list of blog posts. The database has many posts, so you want to implement efficient pagination to avoid slow responses.Keyset pagination is a technique that uses the last seen item's unique ID to fetch the next set of results quickly, instead of using offset-based pagination which can be slow on large datasets.

🎯 Goal: Build a simple REST API endpoint that returns blog posts using keyset pagination for better performance.You will create the initial data, set up a pagination limit, implement the keyset pagination logic, and finally output the paginated results.

📋 What You'll Learn

Create a list of blog posts with exact IDs and titles

Set a pagination limit variable

Implement keyset pagination logic using the last seen post ID

Print the paginated list of posts

💡 Why This Matters

🌍 Real World

Keyset pagination is used in APIs to efficiently load large lists of data without performance issues caused by offset pagination.

💼 Career

Understanding keyset pagination is important for backend developers working on scalable APIs and database querying.

1

Create the initial list of blog posts

Create a list called posts with these exact dictionaries representing blog posts: {'id': 1, 'title': 'Intro to REST'}, {'id': 2, 'title': 'Advanced REST'}, {'id': 3, 'title': 'REST Best Practices'}, {'id': 4, 'title': 'REST Security'}, {'id': 5, 'title': 'REST Performance'}.

Rest API

# Create the list of posts with exact IDs and titles
# Your code here

Need a hint?

Use a list of dictionaries. Each dictionary must have keys 'id' and 'title' with the exact values.

2

Set the pagination limit

Create a variable called limit and set it to 2 to control how many posts to return per page.

Rest API

posts = [
    {'id': 1, 'title': 'Intro to REST'},
    {'id': 2, 'title': 'Advanced REST'},
    {'id': 3, 'title': 'REST Best Practices'},
    {'id': 4, 'title': 'REST Security'},
    {'id': 5, 'title': 'REST Performance'}
]
# Set the pagination limit to 2
# Your code here

Need a hint?

Just create a variable named limit and assign the number 2.

3

Implement keyset pagination logic

Create a variable called last_seen_id and set it to 2. Then create a list called paginated_posts that contains posts from posts where the post 'id' is greater than last_seen_id, limited to limit posts.

Rest API

posts = [
    {'id': 1, 'title': 'Intro to REST'},
    {'id': 2, 'title': 'Advanced REST'},
    {'id': 3, 'title': 'REST Best Practices'},
    {'id': 4, 'title': 'REST Security'},
    {'id': 5, 'title': 'REST Performance'}
]
limit = 2
# Set last_seen_id to 2
# Create paginated_posts with posts having id > last_seen_id limited by limit
# Your code here

Need a hint?

Use a list comprehension to filter posts with id greater than last_seen_id and slice the list to the limit.

4

Print the paginated posts

Write a print statement to display the paginated_posts list.

Rest API

posts = [
    {'id': 1, 'title': 'Intro to REST'},
    {'id': 2, 'title': 'Advanced REST'},
    {'id': 3, 'title': 'REST Best Practices'},
    {'id': 4, 'title': 'REST Security'},
    {'id': 5, 'title': 'REST Performance'}
]
limit = 2
last_seen_id = 2
paginated_posts = [post for post in posts if post['id'] > last_seen_id][:limit]
# Print the paginated_posts list
# Your code here

Need a hint?

Use print(paginated_posts) to show the filtered posts.