org.apache.solr.search.similarities

Class LegacyBM25SimilarityFactory

java.lang.Object

org.apache.solr.schema.SimilarityFactory

org.apache.solr.search.similarities.LegacyBM25SimilarityFactory

public class LegacyBM25SimilarityFactory
extends SimilarityFactory

Factory for LegacyBM25Similarity. Use this to force explicit creation of the BM25 formula that was used by BM25Similarity before Solr/Lucene 8.0.0. Note that SchemaSimilarityFactory will automatically create an instance of LegacyBM25Similarity if luceneMatchVersion is < 8.0.0

Parameters:

• k1 (float): Controls non-linear term frequency normalization (saturation). The default is 1.2
• b (float): Controls to what degree document length normalizes tf values. The default is 0.75

Optional settings:

• discountOverlaps (bool): Sets LegacyBM25Similarity.setDiscountOverlaps(boolean)

Since:

8.0.0

WARNING: This API is experimental and might change in incompatible ways in the next release.

Field Summary

Fields inherited from class org.apache.solr.schema.SimilarityFactory

CLASS_NAME, params

Constructor Summary

Constructors

Constructor and Description
LegacyBM25SimilarityFactory()

Method Summary

Modifier and Type	Method and Description
Similarity	getSimilarity()
void	init(SolrParams params)

Methods inherited from class org.apache.solr.schema.SimilarityFactory

getClassArg, getNamedPropertyValues, getParams

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

LegacyBM25SimilarityFactory

public LegacyBM25SimilarityFactory()

Method Detail

init

public void init(SolrParams params)

Overrides:

init in class SimilarityFactory

getSimilarity

public Similarity getSimilarity()

Specified by:

getSimilarity in class SimilarityFactory