breakdown_by
ChatGPTBreak down a metric by an approved dimension. Row cap: limit 1-50 (default 50). When truncated=true, more groups exist beyond limit_applied; this is a supplier row cap, not an error. For dimension=day, last_30_days and calendar months (≤31 days) fit in one call; do not split the period into multiple requests. If the period spans more days than limit, the earliest N days are returned (ascending date order).
