- validation-prototypes/custom-operator/: NeighborExpand toy operator
with paired ExtensionPlanner + custom QueryPlanner via
SessionStateBuilder::with_query_planner
- writeup at .context/experiments/custom-operator.md: 5 probes
(round-trip, EXPLAIN, predicate guard, composition with Filter +
Aggregate, BaselineMetrics) \u2014 all pass; ~250 LoC integration
footprint; no unsafe; no internal API access
- finding: \u00a75.3 is achievable on DF 52.5 as written; deltas are
doc-shaped (predicate push-down opt-in, statistics requirement,
Partitioning override)
