org.apache.lucene.search

Class XToParentBlockJoinQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.XToParentBlockJoinQuery

public class XToParentBlockJoinQuery
extends org.apache.lucene.search.Query

This query requires that you index children and parent docs as a single block, using the IndexWriter.addDocuments() or IndexWriter.updateDocuments() API. In each block, the child documents must appear first, ending with the parent document. At search time you provide a Filter identifying the parents, however this Filter must provide an BitSet per sub-reader.

Once the block index is built, use this query to wrap any sub-query matching only child docs and join matches in that child document space up to the parent document space. You can then use this Query as a clause with other queries in the parent document space.

See ToChildBlockJoinQuery if you need to join in the reverse order.

The child documents must be orthogonal to the parent documents: the wrapped child query must never return a parent document.

See org.apache.lucene.search.join for an overview.

Constructor Summary

Constructors

Constructor and Description
XToParentBlockJoinQuery(org.apache.lucene.search.Query childQuery, org.apache.lucene.search.join.BitSetProducer parentsFilter, org.apache.lucene.search.join.ScoreMode scoreMode) Create a ToParentBlockJoinQuery.

Method Summary

Modifier and Type	Method and Description
org.apache.lucene.search.Weight	createWeight(org.apache.lucene.search.IndexSearcher searcher, boolean needsScores)
boolean	equals(java.lang.Object other)
org.apache.lucene.search.Query	getChildQuery() Return our child query.
int	hashCode()
org.apache.lucene.search.Query	rewrite(org.apache.lucene.index.IndexReader reader)
java.lang.String	toString(java.lang.String field)

Methods inherited from class org.apache.lucene.search.Query

classHash, sameClassAs, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

XToParentBlockJoinQuery

public XToParentBlockJoinQuery(org.apache.lucene.search.Query childQuery,
                               org.apache.lucene.search.join.BitSetProducer parentsFilter,
                               org.apache.lucene.search.join.ScoreMode scoreMode)

Create a ToParentBlockJoinQuery.

Parameters:

childQuery - Query matching child documents.

parentsFilter - Filter identifying the parent documents.

scoreMode - How to aggregate multiple child scores into a single parent score.

Method Detail

createWeight

public org.apache.lucene.search.Weight createWeight(org.apache.lucene.search.IndexSearcher searcher,
                                                    boolean needsScores)
                                             throws java.io.IOException

Overrides:

createWeight in class org.apache.lucene.search.Query

Throws:

java.io.IOException

getChildQuery

public org.apache.lucene.search.Query getChildQuery()

Return our child query.

rewrite

public org.apache.lucene.search.Query rewrite(org.apache.lucene.index.IndexReader reader)
                                       throws java.io.IOException

Overrides:

rewrite in class org.apache.lucene.search.Query

Throws:

java.io.IOException

toString

public java.lang.String toString(java.lang.String field)

Specified by:

toString in class org.apache.lucene.search.Query

equals

public boolean equals(java.lang.Object other)

Specified by:

equals in class org.apache.lucene.search.Query

hashCode

public int hashCode()

Specified by:

hashCode in class org.apache.lucene.search.Query