In Lucene 5.0, we improved the execution path for queries that run costly operations on a per-document basis, like phrase queries or doc values queries. But we have another class of costly queries, that return fine iterators, but these iterators are very expensive to build. This is typically the case for queries that leverage DocIdSetBuilder, like TermsQuery, multi-term queries or the new point queries. Intersecting such queries with a selective query is very inefficient since these queries build a doc id set of matching documents for the entire index.
Is there something we could do to improve the execution path for these queries?
One idea that comes to mind is that most of these queries could also run on doc values, so maybe we could come up with something that would help decide how to run a query based on other parts of the query? (Just thinking out loud, other ideas are very welcome)