[LUCENE-5424] FilteredQuery useRandomAccess() should use cost()

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Component/s: core/query/scoring
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: David Smiley
• Created: 30/Jan/14 17:00
• Updated: 28/Aug/22 13:59
• Resolved: 20/Oct/14 13:10

Description

Now that Lucene's DISI has a cost() method, it's possible for FilteredQuery's RANDOM_ACCESS_FILTER_STRATEGY to use a smarter algorithm in its useRandomAccess() method. In particular, it might examine filterIter.cost() to see if it is greater than the cost returned by weight.scorer().cost() of the query.

Issue Links

• depends upon: LUCENE-4607 Add estimateDocCount to DocIdSetIterator
• is related to: LUCENE-4410 Make FilteredQuery more flexible with regards to how filters are applied
• is superceded by: LUCENE-5979 Use the cost API instead of a heuristic on the first document in FilteredQuery to decide on whether to use random access
• relates to: LUCENE-5460 Allow driving a query by sparse filters