C# Class Lucene.Net.Join.ToParentBlockJoinCollector

Collects parent document hits for a Query containing one more more BlockJoinQuery clauses, sorted by the specified parent Sort. Note that this cannot perform arbitrary joins; rather, it requires that all joined documents are indexed as a doc block (using {@link IndexWriter#addDocuments} or {@link IndexWriter#updateDocuments}). Ie, the join is computed at index time.

The parent Sort must only use fields from the parent documents; sorting by field in the child documents is not supported.

You should only use this collector if one or more of the clauses in the query is a ToParentBlockJoinQuery. This collector will find those query clauses and record the matching child documents for the top scoring parent documents.

Multiple joins (star join) and nested joins and a mix of the two are allowed, as long as in all cases the documents corresponding to a single row of each joined parent table were indexed as a doc block.

For the simple star join you can retrieve the TopGroups instance containing each ToParentBlockJoinQuery's matching child documents for the top parent groups, using #getTopGroups. Ie, a single query, which will contain two or more ToParentBlockJoinQuery's as clauses representing the star join, can then retrieve two or more TopGroups instances.

For nested joins, the query will run correctly (ie, match the right parent and child documents), however, because TopGroups is currently unable to support nesting (each group is not able to hold another TopGroups), you are only able to retrieve the TopGroups of the first join. The TopGroups of the nested joins will not be correct. See org.apache.lucene.search.join for a code sample. @lucene.experimental

Inheritance: Lucene.Net.Search.Collector

Exibir arquivo Open project: apache/lucenenet Class Usage Examples

Public Methods

Method	Description
AcceptsDocsOutOfOrder ( ) : bool
Collect ( int parentDoc ) : void
GetTopGroups ( Lucene.Net.Join.ToParentBlockJoinQuery query, Lucene.Net.Search.Sort withinGroupSort, int offset, int maxDocsPerGroup, int withinGroupOffset, bool fillSortFields ) : TopGroups	Returns the TopGroups for the specified BlockJoinQuery. The groupValue of each GroupDocs will be the parent docID for that group. The number of documents within each group is calculated as minimum of `maxDocsPerGroup` and number of matched child documents for that group. Returns null if no groups matched.
GetTopGroupsWithAllChildDocs ( Lucene.Net.Join.ToParentBlockJoinQuery query, Lucene.Net.Search.Sort withinGroupSort, int offset, int withinGroupOffset, bool fillSortFields ) : TopGroups	Returns the TopGroups for the specified BlockJoinQuery. The groupValue of each GroupDocs will be the parent docID for that group. The number of documents within each group equals to the total number of matched child documents for that group. Returns null if no groups matched.
ToParentBlockJoinCollector ( Lucene.Net.Search.Sort sort, int numParentHits, bool trackScores, bool trackMaxScore ) : System	Creates a ToParentBlockJoinCollector. The provided sort must not be null. If you pass true trackScores, all ToParentBlockQuery instances must not use ScoreMode.None.

Private Methods

Method	Description
AccumulateGroups ( int slot, int offset, int maxDocsPerGroup, int withinGroupOffset, Lucene.Net.Search.Sort withinGroupSort, bool fillSortFields ) : TopGroups	Accumulates groups for the BlockJoinQuery specified by its slot.
CopyGroups ( OneGroup og ) : void
Enroll ( Lucene.Net.Join.ToParentBlockJoinQuery query, Lucene.Net.Join.ToParentBlockJoinQuery scorer ) : void
sortQueue ( ) : void

Method Details

AcceptsDocsOutOfOrder() public method

public AcceptsDocsOutOfOrder ( ) : bool
return	bool

Collect() public method

public Collect ( int parentDoc ) : void
parentDoc	int
return	void

GetTopGroups() public method

Returns the TopGroups for the specified BlockJoinQuery. The groupValue of each GroupDocs will be the parent docID for that group. The number of documents within each group is calculated as minimum of maxDocsPerGroup and number of matched child documents for that group. Returns null if no groups matched.

if there is a low-level I/O error

public GetTopGroups ( Lucene.Net.Join.ToParentBlockJoinQuery query, Lucene.Net.Search.Sort withinGroupSort, int offset, int maxDocsPerGroup, int withinGroupOffset, bool fillSortFields ) : TopGroups
query	Lucene.Net.Join.ToParentBlockJoinQuery	Search query
withinGroupSort	Lucene.Net.Search.Sort	Sort criteria within groups
offset	int	Parent docs offset
maxDocsPerGroup	int	Upper bound of documents per group number
withinGroupOffset	int	Offset within each group of child docs
fillSortFields	bool	Specifies whether to add sort fields or not
return	TopGroups

GetTopGroupsWithAllChildDocs() public method

Returns the TopGroups for the specified BlockJoinQuery. The groupValue of each GroupDocs will be the parent docID for that group. The number of documents within each group equals to the total number of matched child documents for that group. Returns null if no groups matched.

if there is a low-level I/O error

public GetTopGroupsWithAllChildDocs ( Lucene.Net.Join.ToParentBlockJoinQuery query, Lucene.Net.Search.Sort withinGroupSort, int offset, int withinGroupOffset, bool fillSortFields ) : TopGroups
query	Lucene.Net.Join.ToParentBlockJoinQuery	Search query
withinGroupSort	Lucene.Net.Search.Sort	Sort criteria within groups
offset	int	Parent docs offset
withinGroupOffset	int	Offset within each group of child docs
fillSortFields	bool	Specifies whether to add sort fields or not
return	TopGroups

ToParentBlockJoinCollector() public method

Creates a ToParentBlockJoinCollector. The provided sort must not be null. If you pass true trackScores, all ToParentBlockQuery instances must not use ScoreMode.None.

public ToParentBlockJoinCollector ( Lucene.Net.Search.Sort sort, int numParentHits, bool trackScores, bool trackMaxScore ) : System
sort	Lucene.Net.Search.Sort
numParentHits	int
trackScores	bool
trackMaxScore	bool
return	System