Hoss Man created SOLR-8271:
------------------------------
Summary: use SchemaSimilarityFactory as default when no explicit
(top level) sim is configured
Key: SOLR-8271
URL: https://issues.apache.org/jira/browse/SOLR-8271
Project: Solr
Issue Type: Improvement
Reporter: Hoss Man
Idea spun out of SOLR-8057...
bq. As far as i can tell, the chief reason SchemaSimilarityFactory wasn't made
the implicit default in IndexSchema when it was introduced is because of how it
differed/differs from DefaultSimilarity/ClassicSimilarity with respect to
multi-clause queries – see SchemaSimilarityFactory's class javadoc notes
relating to {{queryNorm}} and {{coord}}. Users were expected to think about
this trade off when making a concious choice to switch from
DefaultSimilarity/ClassicSimilarity to SchemaSimilarityFactory. But (again,
AFAICT) these discrepencies don't exist between SchemaSimilarityFactory's
PerFieldSimilarityWrapper and BM25Similiarity.
So assuming luceneMatchVersion >= 6.0, and BM25 is implicit default, we should
be able to safely switch to using SchemaSimilarityFactory as our default (which
internally uses BM25 for fieldTypes that don't override) and make it much
easier for people to declare fieldType overrides for the similarity (just edit
the fieldType, w/o also needing to explicitly declare SchemaSimilarityFactory)
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
