[LUCENE-7770] BloomFilteringPostingsFormat should implement seekExact(TermState) to avoid to seek within matching segment/field multiple times

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 5.6
• Component/s: core/codecs
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Yannis Hector
• Created: 07/Apr/17 13:36
• Updated: 28/Aug/22 15:13

Description

BloomFilteringPostingsFormat$BloomFilteredFieldsProducer$BloomFilteredTermsEnum does not reuse the TermState from the initial lookup when a second seek is issued (usually when we have a match and we build the Scorer).

Default implementation of TermsEnum#seekExact(BytesRef term, TermState state) that is used by BF calls the regular seekExact method.

This means that the BloomFilteringPostingsFormat default implementation performs a second lookup for every segment/field that have a match for the term (mostly in the various Weight#scorer implementations).

I don't think it is a big issue as we mostly expect search terms to have a match in a limited number of segment/field. But for few queries it could become inefficient.