"Fossies" - the Fresh Open Source Software Archive  

Source code changes of the file "solr/solr-ref-guide/src/the-dismax-query-parser.adoc" between
solr-8.4.0-src.tgz and solr-8.4.1-src.tgz

About: Solr is the search platform from the Apache Lucene project. Its major features include full-text search, hit highlighting, faceted search, caching, replication, and a web admin interface.

the-dismax-query-parser.adoc  (solr-8.4.0-src.tgz):the-dismax-query-parser.adoc  (solr-8.4.1-src.tgz)
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The only difference between the above examples, is that using the `bq` parameter allows you to specify these extra clauses independently (i.e., as configuration defaults) from the main query. The only difference between the above examples, is that using the `bq` parameter allows you to specify these extra clauses independently (i.e., as configuration defaults) from the main query.
[TIP] [TIP]
[[bq-bf-shortcomings]] [[bq-bf-shortcomings]]
.Additive Boosts vs Multiplicative Boosts .Additive Boosts vs Multiplicative Boosts
==== ====
Generally speaking, using `bq` (or `bf`, below) is considered a poor way to "boo st" documents by a secondary query because it has an "Additive" effect on the fi nal score. The overall impact a particular `bq` parameter will have on a given document can vary a lot depending on the _absolute_ values of the scores from th e original query as well as the `bq` query, which in turn depends on the complex ity of the original query, and various scoring factors (TF, IDF, average field l ength, etc.) Generally speaking, using `bq` (or `bf`, below) is considered a poor way to "boo st" documents by a secondary query because it has an "Additive" effect on the fi nal score. The overall impact a particular `bq` parameter will have on a given document can vary a lot depending on the _absolute_ values of the scores from th e original query as well as the `bq` query, which in turn depends on the complex ity of the original query, and various scoring factors (TF, IDF, average field l ength, etc.)
"Multiplicative Boosting" is generally considered to be a more predictable metho d of influcing document score, because it acts as a "scaling factor" -- increasi ng (or decreasing) the scores of each document by a _relative_ amount. "Multiplicative Boosting" is generally considered to be a more predictable metho d of influencing document score, because it acts as a "scaling factor" -- increa sing (or decreasing) the scores of each document by a _relative_ amount.
The <<other-parsers.adoc#boost-query-parser,`{!boost}` QParser>> provides a conv inient wrapper for implementing multiplicitive boosting, and the <<the-extended- dismax-query-parser.adoc#extended-dismax-parameters,`{!edismax}` QParser>> offer s a `boost` query parameter shortcut for using it. The <<other-parsers.adoc#boost-query-parser,`{!boost}` QParser>> provides a conv enient wrapper for implementing multiplicative boosting, and the <<the-extended- dismax-query-parser.adoc#extended-dismax-parameters,`{!edismax}` QParser>> offer s a `boost` query parameter shortcut for using it.
==== ====
=== bf (Boost Functions) Parameter === bf (Boost Functions) Parameter
The `bf` parameter specifies functions (with optional <<the-standard-query-parse r.adoc#boosting-a-term-with,query boost>>) that will be used to construct Functi onQueries which will be _added_ to the user's main query as optional clauses tha t will influence the score. Any <<function-queries.adoc#available-functions,func tion supported natively by Solr>> can be used, along with a boost value. For exa mple: The `bf` parameter specifies functions (with optional <<the-standard-query-parse r.adoc#boosting-a-term-with,query boost>>) that will be used to construct Functi onQueries which will be _added_ to the user's main query as optional clauses tha t will influence the score. Any <<function-queries.adoc#available-functions,func tion supported natively by Solr>> can be used, along with a boost value. For exa mple:
[source,text] [source,text]
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q=cheese q=cheese
bf=div(1,sum(1,price))^1.5 bf=div(1,sum(1,price))^1.5
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