Hm, I hadn't really thought about the minShouldMatch part, I thought it' d be covered but I see your point being semantically different if you keep it as is. However.. Running your edge case example on an actual local index I get the following: "(X X Y #X)" w/minshouldmatch=2 vs. (+X X Y) w/minshouldmatch=2 => same top score, less results in second case."(X X Y #X)" w/minshouldmatch=2 vs. (+X X Y) w/minshouldmatch=1 => same top score, same number of results"(X X X Y #X)" w/minshouldmatch=3 vs. (+X X X Y) w/minshouldmatch=2 => same top score, same number of results But still not really convinced myself if decrementing minshouldmatch by 1 will do the trick.. I'll have to verify - maybe I'll try more examples to see if it holds as a general case.. Nice exercise either way :) On Tuesday, August 9, 2016 12:40 AM, Chris Hostetter wrote: Off the top of my head, i think any optimiation like that would also need to account for minNrShouldMatch, wouldn't it? if your query is "(X Y Z #X)" w/minshouldmatch=2, and you rewrite that query to "(+X Y Z)" w/minshouldmatch=2 you now have a semantically diff query that won't match as many documents as the original. in that example, you could decrement minshouldmatch (=1) ... but i'm not sure off that holds as a general rule for all possible permutations/values ... i'd have to think about it. An interesting edge case to think about is "(X X Y #X)" w/minshouldmatch=2 ... pretty sure that would give you very diff scores if you rewrote it to "(+X X Y)" (or "(+X Y)") w/minshouldmatch=1 : Hello all, I noticed while debugging a query that BooleanQuery will : rewrite itself to remove FILTER clauses that are also MUST as an : optimization/simplification, which makes total sense. So (+f:x #f:x) : will become (+f:x). However, shouldn't there also be another : optimization to remove FILTER clauses that are also SHOULD, while : converting them to MUST? So, for eg. query (f:x #f:x) will become : (+f:x). I did an initial simple implementation and the tests seem to : pass. Are there any cases where this does not hold?  : : -Hoss http://www.lucidworks.com/ --------------------------------------------------------------------- To unsubscribe, e-mail: java-user-unsubscribe@lucene.apache.org For additional commands, e-mail: java-user-help@lucene.apache.org