Hash Joins are a foundational join technology, now available in MySQL!

  • No index maintenance overhead.Can be orders of magnitude faster.Available for ad-hoc workloads and ETL.
  • Great complement to index join operations.

However, the underlying implementation is fundamentally different and introduces additional tweaks to optimize performance.
This presentation will give you the tools to learn when to use Hash Joins and the settings to maximize performance. Hash Joins complement index-join operations: learn the sweet spot for each and what drives that trade-off. This will include a feature comparison across data technologies including MySQL, MariaDB, and Postgres to help understand which Hash Join features have been successfully implemented, what features may need additional work, and what features should be prioritized on the A great roadmap.