~/talk

JOINs Are Slowing You Down: Why Spark and Trino Won’t Replace Your DWH

TalkinRussianat Saint HighLoad++ 2025 · 2025-06-23..06-24· [databases, data-visualization]
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slides:none on file

Examines why JOIN-heavy workloads can be slow and why query engines like Apache Spark and Trino may not be suitable substitutes for a dedicated data warehouse. Explains how query execution engines work, what execution-engine characteristics (beyond RPS and cluster fault-tolerance) affect query behavior and performance, and how those factors influence database selection and tuning.

AI-written summary · about

  1. 0:00Introduction
  2. 1:12Join problem and combinatorics
  3. 3:18Cost-based optimizer
  4. 5:25Top-down vs bottom-up
  5. 8:59Implementation phase
  6. 11:05Join topology and star schemas
  7. 12:10Bottom-up algorithms
  8. 15:23Evolution of bottom-up
  9. 17:08Foreign keys and data vaults
  10. 18:29Statistics in optimization
  11. 23:04Trino vs Spark vs Greenplum
  12. 29:21IDB architecture
  13. 31:50Summary
  14. 34:43Q&A
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