Package org.apache.druid.sql.calcite.aggregation.builtin

Class SimpleSqlAggregator

java.lang.Object

org.apache.druid.sql.calcite.aggregation.builtin.SimpleSqlAggregator

All Implemented Interfaces:

SqlAggregator

Direct Known Subclasses:

MaxSqlAggregator, MinSqlAggregator, SingleValueSqlAggregator, SumSqlAggregator

public abstract class SimpleSqlAggregator
extends Object
implements SqlAggregator

Abstraction for single column, single argument simple aggregators like sum, avg, min, max that: 1) Can take direct field accesses or expressions as inputs. 2) Cannot implicitly cast strings to numbers when using a direct field access.

See Also:

• for details on these requirements

Constructor Summary

Constructors

Constructor	Description
SimpleSqlAggregator()

Method Summary

Modifier and Type	Method	Description
static DruidException	badTypeException(String columnName, String agg, ColumnType type)
Aggregation	toDruidAggregation(PlannerContext plannerContext, VirtualColumnRegistry virtualColumnRegistry, String name, org.apache.calcite.rel.core.AggregateCall aggregateCall, InputAccessor inputAccessor, List<Aggregation> existingAggregations, boolean finalizeAggregations)	Returns a Druid Aggregation corresponding to a SQL AggregateCall.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.apache.druid.sql.calcite.aggregation.SqlAggregator

calciteFunction, toDruidAggregation

Constructor Details

SimpleSqlAggregator

public SimpleSqlAggregator()

Method Details

badTypeException

public static DruidException badTypeException(String columnName,
 String agg,
 ColumnType type)

toDruidAggregation

@Nullable
public Aggregation toDruidAggregation(PlannerContext plannerContext,
 VirtualColumnRegistry virtualColumnRegistry,
 String name,
 org.apache.calcite.rel.core.AggregateCall aggregateCall,
 InputAccessor inputAccessor,
 List<Aggregation> existingAggregations,
 boolean finalizeAggregations)

Description copied from interface: SqlAggregator

Returns a Druid Aggregation corresponding to a SQL AggregateCall. This method should ignore filters; they will be applied to your aggregator in a later step.

Specified by:

toDruidAggregation in interface SqlAggregator

Parameters:

plannerContext - SQL planner context

virtualColumnRegistry - re-usable virtual column references

name - desired output name of the aggregation

aggregateCall - aggregate call object

inputAccessor - gives access to input fields and schema

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.

finalizeAggregations - true if this query should include explicit finalization for all of its aggregators, where required. This is set for subqueries where Druid's native query layer does not do this automatically.

Returns:

aggregation, or null if the call cannot be translated