Lucene - Core
  1. Lucene - Core
  2. LUCENE-2286

enable DefaultSimilarity.setDiscountOverlaps by default

    Details

    • Type: Improvement Improvement
    • Status: Closed
    • Priority: Major Major
    • Resolution: Fixed
    • Affects Version/s: None
    • Fix Version/s: 3.1, 4.0-ALPHA
    • Component/s: core/query/scoring
    • Labels:
      None
    • Lucene Fields:
      New

      Description

      I think we should enable setDiscountOverlaps in DefaultSimilarity by default.

      If you are using synonyms or commongrams or a number of other 0-posInc-term-injecting methods, these currently screw up your length normalization.
      These terms have a position increment of zero, so they shouldnt count towards the length of the document.

      I've done relevance tests with persian showing the difference is significant, and i think its a big trap to anyone using synonyms, etc: your relevance can actually get worse if you don't flip this boolean flag.

        Activity

        Grant Ingersoll made changes -
        Status Resolved [ 5 ] Closed [ 6 ]
        Mark Thomas made changes -
        Workflow Default workflow, editable Closed status [ 12564221 ] jira [ 12583991 ]
        Mark Thomas made changes -
        Workflow jira [ 12500132 ] Default workflow, editable Closed status [ 12564221 ]
        Koji Sekiguchi made changes -
        Fix Version/s 3.1 [ 12314822 ]
        Robert Muir made changes -
        Status Open [ 1 ] Resolved [ 5 ]
        Resolution Fixed [ 1 ]
        Robert Muir made changes -
        Assignee Robert Muir [ rcmuir ]
        Michael McCandless made changes -
        Fix Version/s 3.1 [ 12314025 ]
        Robert Muir made changes -
        Field Original Value New Value
        Attachment LUCENE-2286.patch [ 12437001 ]
        Robert Muir created issue -

          People

          • Assignee:
            Robert Muir
            Reporter:
            Robert Muir
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            Watchers:
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            Dates

            • Created:
              Updated:
              Resolved:

              Development