[LUCENE-4571] speedup disjunction with minShouldMatch

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 4.1
• Fix Version/s: 4.3, 6.0
• Component/s: core/search
• Lucene Fields: New
• Assignee: Unassigned
• Reporter: Mikhail Khludnev
• Created: 23/Nov/12 14:59
• Updated: 28/Aug/22 13:32
• Resolved: 22/Mar/13 19:44

Description

even minShouldMatch is supplied to DisjunctionSumScorer it enumerates whole disjunction, and verifies minShouldMatch condition on every doc:

  public int nextDoc() throws IOException {
    assert doc != NO_MORE_DOCS;
    while(true) {
      while (subScorers[0].docID() == doc) {
        if (subScorers[0].nextDoc() != NO_MORE_DOCS) {
          heapAdjust(0);
        } else {
          heapRemoveRoot();
          if (numScorers < minimumNrMatchers) {
            return doc = NO_MORE_DOCS;
          }
        }
      }
      afterNext();
      if (nrMatchers >= minimumNrMatchers) {
        break;
      }
    }
    
    return doc;
  }

spo proposes (as well as I get it) to pop nrMatchers-1 scorers from the heap first, and then push them back advancing behind that top doc. For me the question no.1 is there a performance test for minShouldMatch constrained disjunction.

Sub-Tasks

• BooleanWeight should decide how to execute minNrShouldMatch: Open