skew

The Databricks signature deep-dive. Everyone says 'salting', almost nobody can write the salt correctly or explain why AQE might make hand-salting unnecessary. The full playbook, in the order a senior engineer actually tries it.

Basic salting assumes one side is a small dimension you can explode. When both sides are huge and skewed, exploding either one blows up the cluster. The staff move is to split hot keys out and handle them on a different plan entirely.