Module columnar_stats 

Query-level columnar fast-path counters (observability).

Shared via Arc with the chunks produced by source operators; every DataChunk::evaluate_expression call records a hit (columnar batch path succeeded) or a miss (fell back to per-row evaluation). The miss rate exposes how much of the flat-column promise is actually kept.

Structs

ColumnarStats

Query-level columnar fast-path counters (observability).

ColumnarStatsSnapshot

Point-in-time snapshot of the columnar fast-path counters for PROFILE.

Constants

D1_EVAL_THRESHOLD

Constants for typed-column analysis.

D1_TYPED_RATE_THRESHOLD

SELECTION_BOUNDARY_OPS

Closed enumeration of opaque operator boundaries that materialize a selection vector. Each entry pairs a display name (used by callers via materialize_selection_by("Name")) with a per-query counter slot.