# Uses of Package
org.apache.lucene.search.grouping

Classes in org.apache.lucene.search.grouping used by org.apache.lucene.search.grouping
Class
Description
AllGroupHeadsCollector
This collector specializes in collecting the most relevant document (group head) for each group that matches the query.
AllGroupHeadsCollector.GroupHead
Represents a group head.
CollectedSearchGroup
Expert: representation of a group in `FirstPassGroupingCollector`, tracking the top doc and `FieldComparator` slot.
DistinctValuesCollector.GroupCount
Returned by `DistinctValuesCollector.getGroups()`, representing the value and set of distinct values for the group.
DoubleRange
Represents a contiguous range of double values, with an inclusive minimum and exclusive maximum
DoubleRangeFactory
Groups double values into ranges
GroupDocs
Represents one group in the results.
GroupFacetCollector
Base class for computing grouped facets.
GroupFacetCollector.FacetEntry
Represents a facet entry with a value and a count.
GroupFacetCollector.GroupedFacetResult
The grouped facet result.
GroupFacetCollector.SegmentResult
Contains the local grouped segment counts for a particular segment.
GroupingSearch
Convenience class to perform grouping in a non distributed environment.
GroupReducer
Concrete implementations of this class define what to collect for individual groups during the second-pass of a grouping search.
GroupSelector
Defines a group, for use by grouping collectors
GroupSelector.State
What to do with the current value
LongRange
Represents a contiguous range of long values, with an inclusive minimum and exclusive maximum
LongRangeFactory
Groups double values into ranges
SearchGroup
Represents a group that is found during the first pass search.
SecondPassGroupingCollector
SecondPassGroupingCollector runs over an already collected set of groups, further applying a `GroupReducer` to each group
TermGroupFacetCollector
An implementation of `GroupFacetCollector` that computes grouped facets based on the indexed terms from DocValues.
TopGroups
Represents result returned by a grouping search.
TopGroups.ScoreMergeMode
How the GroupDocs score (if any) should be merged.