io.druid.sql.calcite.aggregation

Interface SqlAggregator

All Known Implementing Classes:

ApproxCountDistinctSqlAggregator, QuantileSqlAggregator

public interface SqlAggregator

Bridge between Druid and SQL aggregators.

Method Summary

Modifier and Type	Method and Description
org.apache.calcite.sql.SqlAggFunction	calciteFunction() Returns the SQL operator corresponding to this aggregation function.
Aggregation	toDruidAggregation(String name, RowSignature rowSignature, PlannerContext plannerContext, List<Aggregation> existingAggregations, org.apache.calcite.rel.core.Project project, org.apache.calcite.rel.core.AggregateCall aggregateCall, DimFilter filter) Returns Druid Aggregation corresponding to a SQL AggregateCall.

Method Detail

calciteFunction

org.apache.calcite.sql.SqlAggFunction calciteFunction()

Returns the SQL operator corresponding to this aggregation function. Should be a singleton.

Returns:

operator

toDruidAggregation

@Nullable
Aggregation toDruidAggregation(String name,
                                         RowSignature rowSignature,
                                         PlannerContext plannerContext,
                                         List<Aggregation> existingAggregations,
                                         org.apache.calcite.rel.core.Project project,
                                         org.apache.calcite.rel.core.AggregateCall aggregateCall,
                                         DimFilter filter)

Returns Druid Aggregation corresponding to a SQL AggregateCall.

Parameters:

name - desired output name of the aggregation

rowSignature - signature of the rows being aggregated

plannerContext - SQL planner context

existingAggregations - existing aggregations for this query; useful for re-using aggregations. May be safely ignored if you do not want to re-use existing aggregations.

project - SQL projection to apply before the aggregate call, may be null

aggregateCall - SQL aggregate call

filter - filter that should be applied to the aggregation, may be null

Returns:

aggregation, or null if the call cannot be translated