Package org.apache.druid.query.topn
package org.apache.druid.query.topn
-
ClassDescriptionThis
TopNAlgorithmis tailored to processing aggregates on high cardility columns which are likely to have larger result sets.BaseTopNAlgorithm<DimValSelector,DimValAggregateStore, Parameters extends TopNParams> Heap based topn algorithm that handles aggregates on dimension extractions and numeric typed dimension columns.Historical1AggPooledTopNScanner<DimensionSelectorType extends HistoricalDimensionSelector,MetricSelectorType, BufferAggregatorType extends BufferAggregator> ThisTopNAlgorithmis highly specialized for processing aggregates on string columns that areColumnCapabilities.isDictionaryEncoded()andColumnCapabilities.areDictionaryValuesUnique().TopNAlgorithm<DimValSelector,Parameters extends TopNParams> A Builder for TopNQuery.Configuration for TopN queries.Specialization ofQueryMetricsforTopNQuery.Implementations could be injected using PolyBind .optionBinder(binder, Key.get(TopNQueryMetricsFactory.class)) .addBinding("myCustomTopNQueryMetricsFactory") .to(MyCustomTopNQueryMetricsFactory.class); And then setting property: druid.query.topN.queryMetricsFactory=myCustomTopNQueryMetricsFactory