"Cut by a limit", "too large" or "took longer than…"
An answer that is too large is cut and says so; a source that is too large, or an answer that takes too long, is refused with the reason.
Cut by a limit
An answer is cut when it is too large: a field shows 2,000 items at most and a pivot 50,000 cells. What was cut is said above the grid, and the totals still cover every record.
To see what was cut: filter the field, group it (a date by years rather than days), or take a field out.
Refused
A source of more than 500,000 records, or an answer that takes more than 15 seconds, is refused with the reason: nothing partial is shown. Narrow it with Which records?, or use fewer fields.
The Tenant's Config values set these (pivot.maxItemsPerField, pivot.maxCells, pivot.maxSourceRecords, pivot.statementTimeoutMs). To change them, contact the Tenant administrator.