documentsRead

Documents whose bytes were examined: scanned, rechecked, or opened for a projection.

Zero is reachable, and its conditions are worth stating because they are the phase's claim: a fully covered store with nothing unflushed, a plan whose indexes decided every candidate outright, keys unique to their segment, and a projection asking for no document — or asking only for fields a shredded column can give back exactly. See rowsProjectedFromColumns.