Class GroupingSearch
- java.lang.Object
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- org.apache.lucene.search.grouping.GroupingSearch
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public class GroupingSearch extends Object
Convenience class to perform grouping in a non distributed environment.- WARNING: This API is experimental and might change in incompatible ways in the next release.
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Constructor Summary
Constructors Constructor Description GroupingSearch(String groupField)
Constructs aGroupingSearch
instance that groups documents by index terms using DocValues.GroupingSearch(ValueSource groupFunction, Map<Object,Object> valueSourceContext)
Constructs aGroupingSearch
instance that groups documents by function using aValueSource
instance.GroupingSearch(GroupSelector<?> groupSelector)
Constructs aGroupingSearch
instance that groups documents using aGroupSelector
GroupingSearch(Query groupEndDocs)
Constructor for grouping documents by doc block.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description GroupingSearch
disableCaching()
Disables any enabled cache.Bits
getAllGroupHeads()
Returns the matching group heads ifsetAllGroupHeads(boolean)
was set to true or an empty bit set.<T> Collection<T>
getAllMatchingGroups()
IfsetAllGroups(boolean)
was set totrue
then all matching groups are returned, otherwise an empty collection is returned.protected TopGroups<?>
groupByDocBlock(IndexSearcher searcher, Query query, int groupOffset, int groupLimit)
protected TopGroups
groupByFieldOrFunction(IndexSearcher searcher, Query query, int groupOffset, int groupLimit)
<T> TopGroups<T>
search(IndexSearcher searcher, Query query, int groupOffset, int groupLimit)
Executes a grouped search.GroupingSearch
setAllGroupHeads(boolean allGroupHeads)
Whether to compute all group heads (most relevant document per group) matching the query.GroupingSearch
setAllGroups(boolean allGroups)
Whether to also compute all groups matching the query.GroupingSearch
setCaching(int maxDocsToCache, boolean cacheScores)
Enables caching for the second pass search.GroupingSearch
setCachingInMB(double maxCacheRAMMB, boolean cacheScores)
Enables caching for the second pass search.GroupingSearch
setGroupDocsLimit(int groupDocsLimit)
Specifies the number of documents to return inside a group from the specified groupDocsOffset.GroupingSearch
setGroupDocsOffset(int groupDocsOffset)
Specifies the offset for documents inside a group.GroupingSearch
setGroupSort(Sort groupSort)
Specifies how groups are sorted.GroupingSearch
setIncludeMaxScore(boolean includeMaxScore)
Whether to include the score of the most relevant document per group.GroupingSearch
setSortWithinGroup(Sort sortWithinGroup)
Specified how documents inside a group are sorted.
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Constructor Detail
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GroupingSearch
public GroupingSearch(String groupField)
Constructs aGroupingSearch
instance that groups documents by index terms using DocValues. The group field can only have one token per document. This means that the field must not be analysed.- Parameters:
groupField
- The name of the field to group by.
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GroupingSearch
public GroupingSearch(GroupSelector<?> groupSelector)
Constructs aGroupingSearch
instance that groups documents using aGroupSelector
- Parameters:
groupSelector
- aGroupSelector
that defines groups for this GroupingSearch
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GroupingSearch
public GroupingSearch(ValueSource groupFunction, Map<Object,Object> valueSourceContext)
Constructs aGroupingSearch
instance that groups documents by function using aValueSource
instance.- Parameters:
groupFunction
- The function to group by specified asValueSource
valueSourceContext
- The context of the specified groupFunction
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GroupingSearch
public GroupingSearch(Query groupEndDocs)
Constructor for grouping documents by doc block. This constructor can only be used when documents belonging in a group are indexed in one block.- Parameters:
groupEndDocs
- The query that marks the last document in all doc blocks
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Method Detail
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search
public <T> TopGroups<T> search(IndexSearcher searcher, Query query, int groupOffset, int groupLimit) throws IOException
Executes a grouped search. Both the first pass and second pass are executed on the specified searcher.- Parameters:
searcher
- TheIndexSearcher
instance to execute the grouped search on.query
- The query to execute with the groupinggroupOffset
- The group offsetgroupLimit
- The number of groups to return from the specified group offset- Returns:
- the grouped result as a
TopGroups
instance - Throws:
IOException
- If any I/O related errors occur
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groupByFieldOrFunction
protected TopGroups groupByFieldOrFunction(IndexSearcher searcher, Query query, int groupOffset, int groupLimit) throws IOException
- Throws:
IOException
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groupByDocBlock
protected TopGroups<?> groupByDocBlock(IndexSearcher searcher, Query query, int groupOffset, int groupLimit) throws IOException
- Throws:
IOException
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setCachingInMB
public GroupingSearch setCachingInMB(double maxCacheRAMMB, boolean cacheScores)
Enables caching for the second pass search. The cache will not grow over a specified limit in MB. The cache is filled during the first pass searched and then replayed during the second pass searched. If the cache grows beyond the specified limit, then the cache is purged and not used in the second pass search.- Parameters:
maxCacheRAMMB
- The maximum amount in MB the cache is allowed to holdcacheScores
- Whether to cache the scores- Returns:
this
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setCaching
public GroupingSearch setCaching(int maxDocsToCache, boolean cacheScores)
Enables caching for the second pass search. The cache will not contain more than the maximum specified documents. The cache is filled during the first pass searched and then replayed during the second pass searched. If the cache grows beyond the specified limit, then the cache is purged and not used in the second pass search.- Parameters:
maxDocsToCache
- The maximum number of documents the cache is allowed to holdcacheScores
- Whether to cache the scores- Returns:
this
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disableCaching
public GroupingSearch disableCaching()
Disables any enabled cache.- Returns:
this
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setGroupSort
public GroupingSearch setGroupSort(Sort groupSort)
Specifies how groups are sorted. Defaults toSort.RELEVANCE
.- Parameters:
groupSort
- The sort for the groups.- Returns:
this
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setSortWithinGroup
public GroupingSearch setSortWithinGroup(Sort sortWithinGroup)
Specified how documents inside a group are sorted. Defaults toSort.RELEVANCE
.- Parameters:
sortWithinGroup
- The sort for documents inside a group- Returns:
this
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setGroupDocsOffset
public GroupingSearch setGroupDocsOffset(int groupDocsOffset)
Specifies the offset for documents inside a group.- Parameters:
groupDocsOffset
- The offset for documents inside a- Returns:
this
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setGroupDocsLimit
public GroupingSearch setGroupDocsLimit(int groupDocsLimit)
Specifies the number of documents to return inside a group from the specified groupDocsOffset.- Parameters:
groupDocsLimit
- The number of documents to return inside a group- Returns:
this
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setIncludeMaxScore
public GroupingSearch setIncludeMaxScore(boolean includeMaxScore)
Whether to include the score of the most relevant document per group.- Parameters:
includeMaxScore
- Whether to include the score of the most relevant document per group- Returns:
this
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setAllGroups
public GroupingSearch setAllGroups(boolean allGroups)
Whether to also compute all groups matching the query. This can be used to determine the number of groups, which can be used for accurate pagination.When grouping by doc block the number of groups are automatically included in the
TopGroups
and this option doesn't have any influence.- Parameters:
allGroups
- to also compute all groups matching the query- Returns:
this
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getAllMatchingGroups
public <T> Collection<T> getAllMatchingGroups()
IfsetAllGroups(boolean)
was set totrue
then all matching groups are returned, otherwise an empty collection is returned.- Type Parameters:
T
- The group value type. This can be aBytesRef
or aMutableValue
instance. If grouping by doc block this the group value is alwaysnull
.- Returns:
- all matching groups are returned, or an empty collection
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setAllGroupHeads
public GroupingSearch setAllGroupHeads(boolean allGroupHeads)
Whether to compute all group heads (most relevant document per group) matching the query.This feature isn't enabled when grouping by doc block.
- Parameters:
allGroupHeads
- Whether to compute all group heads (most relevant document per group) matching the query- Returns:
this
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getAllGroupHeads
public Bits getAllGroupHeads()
Returns the matching group heads ifsetAllGroupHeads(boolean)
was set to true or an empty bit set.- Returns:
- The matching group heads if
setAllGroupHeads(boolean)
was set to true or an empty bit set
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