[jira] [Created] (LUCENE-5460) Allow driving a query by sparse filters

["Shai Erera (JIRA)" <ji...@apache.org>]

Shai Erera created LUCENE-5460:
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             Summary: Allow driving a query by sparse filters
                 Key: LUCENE-5460
                 URL: https://issues.apache.org/jira/browse/LUCENE-5460
             Project: Lucene - Core
          Issue Type: Improvement
          Components: core/search
            Reporter: Shai Erera


Today if a filter is very sparse we execute the query in sort of a leap-frog manner between the query and filter. If the query is very expensive to compute, and/or matching few docs only too, calling scorer.advance(doc) just to discover the doc it landed on isn't accepted by the filter, is a waste of time. Since Filter is always the "final ruler", I wonder if we had something like {{boolean DISI.advanceExact(doc)}} we could use it instead, in some cases.

There are many combinations in which I think we'd want to use/not-use this API, and they depend on: Filter's complexity, Filter.cost(), Scorer.cost(), query complexity (span-near, many clauses) etc.

I open an issue so we can discuss. DISI.advanceExact(doc) is just a preliminary proposal, to get an API we could experiment with. The default implementation should be fairly easy and straightforward, and we could override where we can offer a more optimized imp.



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