Projections in ClickHouse
Mark Needham
Discover how to dramatically improve query performance in ClickHouse using projections - a powerful feature that creates query-optimized copies of your data.
This video demonstrates projections using a real-world example with 30 million UK property price records. Watch as we reduce query time from 53 milliseconds to just 4 milliseconds by creating a projection for calculating average house prices by county.
What You'll Learn:
- What projections are and how they work as hidden tables that update atomically
- Three main use cases: reordered datasets, subset of columns filtering, and pre-computed aggregations
- Step-by-step process to create and materialize projections
- How to verify projections are being used with EXPLAIN queries
- Understanding the storage trade-offs and space requirements
ClickHouse at DoorDash
How DoorDash monitors TCP and DNS traffic helping their observability team take care of their kubernetes infrastructure.
ClickHouse v25.10 Release Webinar
Alexey Milovidov
Moderniser l’observabilité avec ClickStack : simplifier, accélérer, innover
L’observabilité n’a jamais été aussi critique… ni aussi complexe. Êtes-vous prêt à transformer votre manière de gérer la complexité des systèmes distribués ? Découvrez comment ClickHouse révolutionne l’observabilité moderne en combinant rapidité, efficacité et ouverture.
