Enhancing WSO2 Identity Server with Cursor-Based Pagination: Key Differences and Benefits 🚀

WSO2 Identity Server and Asgardeo currently utilize offset-based pagination for SCIM 2.0 to list resources. While this method has been effective, we are excited to announce that we are planning on introducing cursor-based pagination to WSO2 IAM products, a feature known for its efficiency and consistency. 🌟 This article will explore what cursor-based pagination is, how it differs from offset-based pagination, and why this upgrade is thrilling for those managing large datasets.

What is Cursor-Based Pagination? 📖
Imagine navigating data without flipping through numbered pages like a thick book. Instead, cursor-based pagination is like placing a bookmark at the last page you read. It uses a cursor (a unique identifier or combination of identifiers) as a pointer to track your position in a dataset. The system then retrieves the next chunk of data starting from where you left off and provides a new cursor to continue. No more losing your place! 🕵️‍♂️

• Sequential Access: Data is retrieved one step at a time, like a conveyor belt, ensuring you don’t miss or duplicate entries, even when new items (users) are added or updated.
• Efficiency: Often more efficient for large datasets as it avoids the need to count or skip records.
• Consistency: Provides more consistent results, especially in dynamic data environments where entries are frequently added, updated, or deleted.

Differences Between Offset-Based and Cursor-Based Pagination Implementations 🔄

Offset-Based Pagination: Specifies an offset (start index) and a count (number of items to return). While simple, it can become inefficient with large datasets, as it requires counting and skipping records, and can lead to inconsistent results when data changes frequently.

Offset-Based Pagination

Cursor-Based Pagination: Uses a cursor (a unique identifier or pointer) to mark the position in the dataset. This approach avoids counting and skipping records, offering more consistent results and improved performance.

Cursor-Based Pagination

In the above examples, the offset-based pagination request retrieves a specified number of items starting from a given offset, while the cursor-based pagination request uses a cursor to retrieve items and provides a new cursor for the next set of items. The cursor-based response includes a nextCursor field that can be used to fetch the next set of results.

Why Cursor-Based Pagination? 🤔
To understand the benefits of cursor-based pagination, consider a scenario where you are managing a large directory of users, with new users being frequently added or updated. With offset-based pagination, you might face the following issues:

• Inconsistent Results: If users are added or removed between requests, the same user might appear on different pages, or some users might be skipped altogether.
• Performance Overhead: Each request requires the server to count and skip a potentially large number of records, which can be resource-intensive.

With cursor-based pagination, these issues are mitigated:

• Consistent Results: Since each page request is based on a cursor pointing to a specific user, the results remain consistent even if new users are added or existing ones are updated.
• Reduced Overhead: The server doesn’t need to count and skip records. It simply retrieves the next set of users starting from the current cursor position, making the process more efficient.

What to Expect When This Feature is Implemented 🔧
When cursor-based pagination is implemented in WSO2 Identity Server, you can expect the following:

• Smooth Transition: The implementation will be designed to minimize disruption and allow for a smooth transition from offset-based to cursor-based pagination.
• Enhanced Documentation: Comprehensive documentation will be provided to help users understand and implement cursor-based pagination in their systems.
• Backward Compatibility: Will be implemented to ensure that existing systems can continue using offset-based pagination if desired.
• Improved Performance: The users will notice significant improvements in performance and consistency, particularly with large datasets and in environments with frequent data updates.

Conclusion 🏁
The introduction of cursor-based pagination in WSO2 Identity Server marks a significant enhancement in how we handle large datasets and frequent data updates. By offering more efficient, consistent, and performant data retrieval, this new feature is set to provide a better user experience and meet the growing demands of modern applications. We are excited about this development and look forward to sharing more details as we move closer to the release! 🎉