Query Plans

explain returns data, not formatted prose. It reports the normalized source bounds, operation steps, streaming status, materialization estimate, and optimizer notes.

Filtering, derivation, :take, :drop, and selection can stream through compile-query. A global :order-by or :group-by requires execute to hold matching results before producing its output. The plan labels this as :estimated-materialization :all-matching-records. Grouping supports :count, :first-date, :last-date, :min-day, and :max-day aggregations.

The current optimizer performs only a semantics-preserving projection cleanup: repeated fields in :select are removed while keeping the first occurrence. It does not rewrite predicate meaning or guess at data statistics.