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https://issues.apache.org/jira/browse/LUCENE-4376?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13453562#comment-13453562
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Robert Muir commented on LUCENE-4376:
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then use a ConstantScoreQuery
> Add Query subclasses for selecting documents where a field is empty or not
> --------------------------------------------------------------------------
>
> Key: LUCENE-4376
> URL: https://issues.apache.org/jira/browse/LUCENE-4376
> Project: Lucene - Core
> Issue Type: Improvement
> Components: core/query/scoring
> Reporter: Jack Krupansky
> Fix For: 5.0
>
>
> Users frequently wish to select documents based on whether a specified
> sparsely-populated field has a value or not. Lucene should provide specific
> Query subclasses that optimize for these two cases, rather than force users
> to guess what workaround might be most efficient. It is simplest for users to
> use a simple pure wildcard term to check for non-empty fields or a negated
> pure wildcard term to check for empty fields, but it has been suggested that
> this can be rather inefficient, especially for text fields with many terms.
> 1. Add NonEmptyFieldQuery - selects all documents that have a value for the
> specified field.
> 2. Add EmptyFieldQuery - selects all documents that do not have a value for
> the specified field.
> The query parsers could turn a pure wildcard query (asterisk only) into a
> NonEmptyFieldQuery, and a negated pure wildcard query into an EmptyFieldQuery.
> Alternatively, maybe PrefixQuery could detect pure wildcard and automatically
> "rewrite" it into NonEmptyFieldQuery.
> My assumption is that if the actual values of the field are not needed,
> Lucene can much more efficiently simply detect whether values are present,
> rather than, for example, the user having to create a separate boolean "has
> value" field that they would query for true or false.
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