Query Costs and Weightings

In order to minimize the risk of reports with excessive content, validation is applied to limit the number of columns that can be selected based on the cost of a column.

Columns with a single value per output row have a cost based solely on the complexity of calculating the value (which for non-calculated columns is near zero); columns where there may be multiple values are significantly more expensive while columns where there may be multiple sets of multiple values are significantly more expensive still.

The columns selected in filters count toward the total, with each row in the filters table incurring a cost. If the limit is exceeded, the following message is shown: Maximum number of report columns exceeded. Please reduce the number of selected columns or filters. The maximum number of rows returned in a report is 200,000.