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https://issues.apache.org/jira/browse/LUCENE-1252?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12713928#action_12713928
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Michael McCandless commented on LUCENE-1252:
--------------------------------------------

I agree, we would want to do a ConjunctionScorer first, w/ all 4 terms, and 
then 2nd a PhraseScorer for each of the two phrases, but somehow they should be 
bound together such that a single TermPositions enumerator is shared in the two 
places for each term.

I think doing the additional filtering in collect is a little late -- there 
could be a number of such "more expensive constraints" to apply, depending on 
the query.

But, eg since we're talking about how to fix the up-front sort logic in 
ConjunctionScorer... you could imagine asking the PhraseQuery for its scorer, 
and getting back 2 AND'd scorers (cheap & expensive) that under-the-hood are 
sharing a single TermPositions enum, and then ConjunctionScorer would order all 
such scorers it got so that all cheap ones are checked first and only once they 
agree on a doc are the expensive scorers check.

> Avoid using positions when not all required terms are present
> -------------------------------------------------------------
>
>                 Key: LUCENE-1252
>                 URL: https://issues.apache.org/jira/browse/LUCENE-1252
>             Project: Lucene - Java
>          Issue Type: Wish
>          Components: Search
>            Reporter: Paul Elschot
>            Priority: Minor
>
> In the Scorers of queries with (lots of) Phrases and/or (nested) Spans, 
> currently next() and skipTo() will use position information even when other 
> parts of the query cannot match because some required terms are not present.
> This could be avoided by adding some methods to Scorer that relax the 
> postcondition of next() and skipTo() to something like "all required terms 
> are present, but no position info was checked yet", and implementing these 
> methods for Scorers that do conjunctions: BooleanScorer, PhraseScorer, and 
> SpanScorer/NearSpans.

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