Hunting Non Optimised Queries in ClickHouse

Yohann Jardin

Data Engineer and Team Lead at Contentsquare Picture this: Months after the migration your teams crafted new features, you ingest more data, and ClickHouse slows down. Should you scale your cluster, or are there inefficient queries ruining the fun of everyone else?

In this talk, we will see how to leverage system tables to hunt non-optimised queries, using manual and Machine Learning assisted strategies, and how we can use clickhouse-benchmark to confirm our hypotheses.