org.apache.lucene.search

Class TermInSetQuery

java.lang.Object

org.apache.lucene.search.Query

org.apache.lucene.search.TermInSetQuery

All Implemented Interfaces:

Accountable

public class TermInSetQuery
extends Query
implements Accountable

Specialization for a disjunction over many terms that behaves like a ConstantScoreQuery over a BooleanQuery containing only BooleanClause.Occur.SHOULD clauses.

For instance in the following example, both @{code q1} and q2 would yield the same scores:

 Query q1 = new TermInSetQuery(new Term("field", "foo"), new Term("field", "bar"));

 BooleanQuery bq = new BooleanQuery();
 bq.add(new TermQuery(new Term("field", "foo")), Occur.SHOULD);
 bq.add(new TermQuery(new Term("field", "bar")), Occur.SHOULD);
 Query q2 = new ConstantScoreQuery(bq);
 

When there are few terms, this query executes like a regular disjunction. However, when there are many terms, instead of merging iterators on the fly, it will populate a bit set with matching docs and return a Scorer over this bit set.

NOTE: This query produces scores that are equal to its boost

Constructor Summary

Constructors

Constructor and Description
TermInSetQuery(String field, BytesRef... terms) Creates a new TermInSetQuery from the given array of terms.
TermInSetQuery(String field, Collection<BytesRef> terms) Creates a new TermInSetQuery from the given collection of terms.

Method Summary

Modifier and Type	Method and Description
Weight	createWeight(IndexSearcher searcher, boolean needsScores, float boost) Expert: Constructs an appropriate Weight implementation for this query.
boolean	equals(Object other) Override and implement query instance equivalence properly in a subclass.
Collection<Accountable>	getChildResources() Returns nested resources of this class.
PrefixCodedTerms	getTermData() Returns the terms wrapped in a PrefixCodedTerms.
int	hashCode() Override and implement query hash code properly in a subclass.
long	ramBytesUsed() Return the memory usage of this object in bytes.
Query	rewrite(IndexReader reader) Expert: called to re-write queries into primitive queries.
String	toString(String defaultField) Prints a query to a string, with field assumed to be the default field and omitted.

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

TermInSetQuery

public TermInSetQuery(String field,
                      Collection<BytesRef> terms)

Creates a new TermInSetQuery from the given collection of terms.

TermInSetQuery

public TermInSetQuery(String field,
                      BytesRef... terms)

Creates a new TermInSetQuery from the given array of terms.

Method Detail

rewrite

public Query rewrite(IndexReader reader)
              throws IOException

Description copied from class: Query

Expert: called to re-write queries into primitive queries. For example, a PrefixQuery will be rewritten into a BooleanQuery that consists of TermQuerys.

Overrides:

rewrite in class Query

Throws:

IOException

equals

public boolean equals(Object other)

Description copied from class: Query

Override and implement query instance equivalence properly in a subclass. This is required so that QueryCache works properly. Typically a query will be equal to another only if it's an instance of the same class and its document-filtering properties are identical that other instance. Utility methods are provided for certain repetitive code.

Specified by:

equals in class Query

See Also:

Query.sameClassAs(Object), Query.classHash()

hashCode

public int hashCode()

Description copied from class: Query

Override and implement query hash code properly in a subclass. This is required so that QueryCache works properly.

Specified by:

hashCode in class Query

See Also:

Query.equals(Object)

getTermData

public PrefixCodedTerms getTermData()

Returns the terms wrapped in a PrefixCodedTerms.

toString

public String toString(String defaultField)

Description copied from class: Query

Prints a query to a string, with field assumed to be the default field and omitted.

Specified by:

toString in class Query

ramBytesUsed

public long ramBytesUsed()

Description copied from interface: Accountable

Return the memory usage of this object in bytes. Negative values are illegal.

Specified by:

ramBytesUsed in interface Accountable

getChildResources

public Collection<Accountable> getChildResources()

Description copied from interface: Accountable

Returns nested resources of this class. The result should be a point-in-time snapshot (to avoid race conditions).

Specified by:

getChildResources in interface Accountable

See Also:

Accountables

createWeight

public Weight createWeight(IndexSearcher searcher,
                           boolean needsScores,
                           float boost)
                    throws IOException

Description copied from class: Query

Expert: Constructs an appropriate Weight implementation for this query.

Only implemented by primitive queries, which re-write to themselves.

Overrides:

createWeight in class Query

needsScores - True if document scores (Scorer.score()) or match frequencies (Scorer.freq()) are needed.

boost - The boost that is propagated by the parent queries.

Throws:

IOException