python scripts/benchmark_freshness.py owns the in-process DuckDB demo
event-to-metric measurement family. The default command writes both mutable
outputs under the ignored runtime artifact directory:
.artifacts/freshness/freshness-benchmark.md— human-readable report;.artifacts/freshness/current.json— machine-readable results.
Re-running the command replaces those runtime files. The script refuses to write either this lifecycle page or the archived snapshot, so a benchmark run cannot silently mutate tracked documentation.
The last report formerly stored at this path is preserved as the immutable
2026-06-06 historical snapshot.
It records the pre-S7 in-process demo shortcut on Windows with
fakeredis-backed cache semantics: 1.06 s p50 and 1.99 s p95 for the
event_driven arm. It does not measure Kafka, Flink, the serving bridge, or
ClickHouse and does not describe current production invalidation wiring.
The complementary archived S8 real-path record measures Kafka through the live metric on the Mac/Colima stand. The two records cover different execution scopes and are not a supersession chain.
Freshness measurements depend on the host, timestamp, and runtime state, so they have no byte-for-byte regeneration check. Promote a release-worthy run only under a date-stamped filename with its JSON companion and exact run/host/source provenance; never recreate a mutable tracked latest report.