solr中的tie breaker

solr 查询参数中有tie这样的一个参数,下面是它的官方解释:

The tie (Tie Breaker) Parameter

The tie parameter specifies a float value (which should be something much less than 1) to use as tiebreaker in DisMax queries.

When a term from the user’s input is tested against multiple fields, more than one field may match. If so, each field will generate a different score based on how common that word is in that field (for each document relative to all other documents). The tie parameter lets you control how much the final score of the query will be influenced by the scores of the lower scoring fields compared to the highest scoring field.

A value of “0.0” makes the query a pure “disjunction max query”: that is, only the maximum scoring subquery contributes to the final score. A value of “1.0” makes the query a pure “disjunction sum query” where it doesn’t matter what the maximum scoring sub query is, because the final score will be the sum of the subquery scores. Typically a low value, such as 0.1, is useful.




如果field1.score= 10,field2.score=3。那么 score = 10 + tie * 3.