Double glazing: Two years of windowing improvements
summary
DuckDB reports two and a half years of concrete windowing changes: new distinct aggregates, exclude and qualify clauses, a streaming evaluator for simple ordered inputs, and lead/lag optimized for offset 1. Performance work adds Partition Fusion, vectorization cleanup and a one‑partition‑at‑a‑time memory reduction that avoids holding many partitions in RAM; parallel data‑structure builds had contention but are mostly resolved and target the 1.1 release. New algorithms include single‑value aggregation, merge‑sort trees and doubly ordered trees for parallel build/query.
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chapters (6)
- 0:00Introduction and overview
- 1:14Understanding windowing
- 2:09Window operator planning
- 3:08Operator performance tuning
- 4:04Aggregation accelerators
- 4:52Advanced optimizations and Q&A
