[LUCENE-9620] Add Weight#count(LeafReaderContext)

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 9.0
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Adrien Grand
• Created: 23/Nov/20 08:56
• Updated: 28/Aug/22 16:10
• Resolved: 07/Sep/21 14:09

Description

We have IndexSearcher#count today, which tries to optimize counting for TermQuery and MatchAllDocsQuery, and falls back to BulkScorer + TotalHitCountCollector otherwise.

I'm considering moving this to Weight instead, where it'd be a better place to add counting optimizations for other queries, e.g. pure disjunctions over single-valued fields or range queries on points. The default implementation could use a BulkScorer+TotalHitCountCollector like IndexSearcher#count does today.

Issue Links

• is depended upon by: LUCENE-10085 Implement Weight#count on DocValuesFieldExistsQuery
• links to: GitHub Pull Request #242