The computed aggregate field specifications
Boolean Indicates if the full cross-product of all groupby values should be included in the aggregate output (default false). If set to true, all possible combinations of groupby field values will be considered and zero count groups will be generated and returned for combinations that do not occur in the data itself. Cross-product output act as if the drop parameter is false. In the case of streaming updates, the number of output groups will increase if new groupby field values are observed; all prior groups will be retained. This parameter can be useful for generating facets that include groups for all possible partitions of the data.
Indicates if empty (zero count) groups should be dropped (default true). When a data stream updates (for example, in response to interactive filtering), aggregation groups may become empty. By default, the group is removed from the output. However, in some cases (such as histograms), one may wish to retain empty groups.
The data fields to group by. If not specified, a single group containing all data objects will be used.
Build the transformation