[Video] Advanced SQL join table cardinality estimates

Hey Community!

We're happy to share a new video from our InterSystems Developers YouTube:

⏯  Advanced SQL join table cardinality estimates @ Ready 2025

https://www.youtube.com/embed/8FE9v7xkEj8
[This is an embedded link, but you cannot view embedded content directly on the site because you have declined the cookies necessary to access it. To view embedded content, you would need to accept all cookies in your Cookies Settings]

Thomas Henchel presents his team’s recent work on improving cardinality estimates in SQL query optimizers - a key factor that affects join ordering and query performance. The team implemented a new state-of-the-art estimation method based on 2023 research. When tested on benchmark queries, most results showed no change, but around 21% of queries ran slower and only about 11% improved. These mixed results highlight challenges in balancing over- and underestimation. The group continues refining optimization techniques to achieve faster, more efficient queries and invites feedback on patterns or concerns from real workloads.

🗣 Presenter: @Thomas Hentschel, Systems Developer, InterSystems

Enjoy watching, and subscribe for more videos! 👍