Refinement ranking of aggregated records

The MDEX Engine uses the aggregated record counts beneath a given refinement for its refinement ranking strategy only if they were computed for the query sent to the MDEX Engine.

The MDEX Engine computes refinement ranking based on statistics for the number of records beneath a given refinement. In the case of aggregated records, refinement ranking depends on whether you have requested the MDEX Engine to compute statistics for aggregated record counts beneath a given refinement.

The following statements describe the behavior:

To enable dynamic statistics for aggregated records (aggregated record counts beneath a given refinement), use the --stat-abins flag with the Dgraph.
To retrieve the aggregated record counts beneath a given refinement, use the DGraph.AggrBins property.
If you specify --stat-abins when starting a Dgraph and issue an aggregated query to the MDEX Engine, it then computes counts for aggregated records beneath a given refinement, and generates refinement ranking based on statistics computed for aggregated records.
If you specify --stat-abins and issue a non-aggregated query to the MDEX Engine, it only computes counts for regular records (instead of aggregated record counts) beneath a given refinement, and generates refinement ranking based on statistics computed for regular records.
If you do not specify --stat-abins and issue an aggregated query to the MDEX Engine, it only computes counts for regular records (instead of aggregated record counts) beneath a given refinement, and generates refinement ranking based on statistics computed for regular records.

To summarize, the MDEX Engine uses the aggregated record counts beneath a given refinement for its refinement ranking strategy only if they were computed. In all other cases, it uses only regular record counts for refinement ranking.