[SOLR-2649] MM ignored in edismax queries with operators

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 5.5, 6.0
• Component/s: query parsers
• Assignee: Erick Erickson
• Reporter: Magnus Bergmark
• Created: 12/Jul/11 12:13
• Updated: 30/Mar/18 00:47
• Resolved: 15/Dec/15 04:51

Description

Hypothetical scenario:
1. User searches for "stocks oil gold" with MM set to "50%"
2. User adds "-stockings" to the query: "stocks oil gold -stockings"
3. User gets no hits since MM was ignored and all terms where AND-ed together

The behavior seems to be intentional, although the reason why is never explained:
// For correct lucene queries, turn off mm processing if there
// were explicit operators (except for AND).
boolean doMinMatched = (numOR + numNOT + numPluses + numMinuses) == 0;
(lines 232-234 taken from tags/lucene_solr_3_3/solr/src/java/org/apache/solr/search/ExtendedDismaxQParserPlugin.java)

This makes edismax unsuitable as an replacement to dismax; mm is one of the primary features of dismax.

Issue Links

• is duplicated by: SOLR-3385 Extended Dismax parser ignores all regular search terms when one search term is using + (dismax behaves differently)
• is part of: SOLR-2368 Improve extended dismax (edismax) parser
• is related to: SOLR-3580 In ExtendedDismax, lowercase 'not' operator is not being treated as an operator when 'lowercaseOperators' is enabled
• is related to: SOLR-12165 Ref Guide: DisMax default mm param value is improperly documented as 100%
• is related to: SOLR-4646 [edismax] let lowercaseOperators default to "false"
• relates to: SOLR-3385 Extended Dismax parser ignores all regular search terms when one search term is using + (dismax behaves differently)
• relates to: SOLR-8812 ExtendedDismaxQParser (edismax) ignores Boolean OR when q.op=AND and mm is not explicitly set