Add document and field boosing at index time in Lucene configuration

[fxp]

• Default GeoNetwork lucence configuration does not set any boosts (ie. not changed)
• This feature has to be used by expert users to alter default search behavior scoring according to catalogue content.
• Add configuration for boosting fields in lucene-config.xml. Some fields are more important than others. This type of configuration will alter OR queries behavior.
  • Configuration: Example to promote title

    <field name="title" boost="1.5F"/>
    

• Add configuration for boosting a document in lucene-config.xml.
  • A use case could be: to promote series and not promote datasets part of a series.
  • A sample boosting class is added: ImportantDocument.
  • Boost factor for a document is computed based on document field and value match.
  • Example 1: the following configuration will
    • Default boost is 1
    • Add .1 to a document having type = series
    • Remove .3 to a document having type = service
    • Add .4 to a document having keyword = Elevation

      <boostDocument name="org.fao.geonet.kernel.search.function.ImportantDocument">
          <Param name="fields" type="java.lang.String" value="type,type,keyword"/>
          <Param name="values" type="java.lang.String" value="series,service,Elevation"/>
          <Param name="boosts" type="java.lang.String" value=".1F,-.3F,.4F"/>
      </boostDocument>
      

  • Example 2: to promote series and not promote datasets part of a series:

    <boostDocument name="org.fao.geonet.kernel.search.function.ImportantDocument">
       <Param name="fields" type="java.lang.String" value="type,parentUuid"/>
        <Param name="values" type="java.lang.String" value="series,NOTNULL"/>
        <Param name="boosts" type="java.lang.String" value=".1F,-.3F"/>
    </boostDocument>
    

[fxp]

Committed revision 8583.