Replace Query with Synonyms
By default Magento appends synonyms to the search query (i.e. Search for “computer” with a synonym configured of “dell computer” and Magento will actually search for “dell computer computer”. This setting will tell Magento to only search for “dell computer”)
Minimum ‘Should’ Match
This setting controls the number of terms.
By default all words or phrases specified in the search query are treated as "optional" clauses. When dealing with these "optional" clauses, the "mm" option makes it possible to say that a certain minimum number of those clauses must match (mm). Specifying this minimum number can be done in complex ways, equating to ideas like...
- At least 2 of the optional clauses must match, regardless of how many clauses there are: "2"
- At least 75% of the optional clauses must match, rounded down: "75%"
- If there are less than 3 optional clauses, they all must match; if there are 3 or more, then 75% must match, rounded up: "2<-25%"
- If there are less than 3 optional clauses, they all must match; for 3 to 5 clauses, one less than the number of clauses must match, for 6 or more clauses, 80% must match, rounded down: "2<-1 5<80%"
- You should basically set this to 0 if you want the equivalent of an OR search, and 100% if you want the equivalent of an AND search
For more info, see: http://wiki.apache.org/solr/DisMaxQParserPlugin#mm_.28Minimum_.27Should.27_Match.29