- All Implemented Interfaces:
- Direct Known Subclasses:
Nested Class Summary
Fields inherited from class org.elasticsearch.search.aggregations.AggregatorBase
collectableSubAggregators, DEFAULT_WEIGHT, name, parent, subAggregators
Methods inherited from class org.elasticsearch.search.aggregations.AggregatorBase
addRequestCircuitBreakerBytes, bigArrays, buildEmptySubAggregations, close, doClose, doPostCollection, doPreCollection, getLeafCollector, metadata, name, parent, pointReaderIfAvailable, postCollection, preCollection, preGetSubLeafCollectors, scoreMode, searcher, subAggregator, subAggregators, topLevelQuery, toString
Methods inherited from class org.elasticsearch.search.aggregations.Aggregator
bucketComparator, buildEmptyAggregation, buildTopLevel, collectDebugInfo, resolveSortPath, resolveSortPathOnValidAgg
getLeafCollectorpublic final LeafBucketCollector getLeafCollector
(org.apache.lucene.index.LeafReaderContext reader, LeafBucketCollector sub)Description copied from class:
AggregatorBaseCollect results for this leaf.
Most Aggregators will return a custom
LeafBucketCollectorthat collects document information for every hit. Callers of this method will make sure to call
collectfor every hit. So any
Aggregatorthat returns a customer LeafBucketCollector from this method runs at best
O(hits)time. See the
sumAggregator for a fairly strait forward example of this.
Some Aggregators are able to correctly collect results on their own, without being iterated by the top level query or the rest of the aggregations framework. These aggregations collect what they need by calling methods on
LeafReaderContextand then they return
LeafBucketCollector.NO_OP_COLLECTORto signal that they've done their own collection. These aggregations can do better than
O(hits). See the
minAggregator for an example of an aggregation that does this. It happens to run in constant time in some cases.
In other cases
MinAggregatorcan't get correct results by taking the constant time path so instead it returns a custom
LeafBucketCollector. This is fairly common for aggregations that have these fast paths because most of these fast paths are only possible when the aggregation is at the root of the tree.
buildAggregationsDescription copied from class:
AggregatorBuild the results of this aggregation.