Deterministic Tiebreaks for Stable Output

Concepts covered: sqlWindowDedup

The last design decision: write-time dedup vs read-time dedup. Write-time stores the deduped target; every consumer reads the deduped data. Read-time stores all rows including duplicates, and each consumer dedupes in their query. Each has a cost; each is right in a different workload. Picking based on read-write ratio is the design conversation. Write-time dedup Pros: every consumer reads clean data; no per-query dedup logic; storage is bounded by unique rows. Cons: the ingestion job is responsible for dedup correctness; bugs in the ingestion dedup affect every downstream; rerunning ingestion against a different dedup logic requires recomputing the target. Right for: high read-to-write ratios, multiple downstream consumers, stable dedup logic. Read-time dedup Pros: source-of-truth retains

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