问题
In my case, documents have two fields, for example, "title" and "views". "views" is represented the num of times that people have visited this document. like: "title":"iphone", "views":"10". I have to develop a strategy that will assign some weights to views, such as the relevance score is calculated by score(title)*0.8+score(views)*0.2. Does lucene can do this? And I want to know whether there are some algorithms related to this question.
回答1:
Here is how you can do that:
Query titleQuery, viewsQuery;
titleQuery.setBoost(0.8);
viewsQuery.setBoost(0.2);
BooleanQuery query = new BooleanQuery();
query.add(titleQuery, Occur.MUST); // or Occur.SHOULD if this clause is optional
query.add(viewsQuery, Occur.SHOULD); // or Occur.MUST if this clause is required
// use query to search documents
The score will be proportional to 0.8*score(titleQuery) + 0.2*score(viewsQuery) (to a multiplicative constant).
To leverage your views field, you will probably need to use a ValueSourceQuery.
回答2:
You can boost in 3 ways. Depending on your needs you might want to employ a combination
Document level boosting - while indexing - by calling document.setBoost() before a document is added to the index.
Document's Field level boosting - while indexing - by calling field.setBoost() before adding a field to the document (and before adding the document to the index).
Query level boosting - during search, by setting a boost on a query clause, calling Query.setBoost().
source: http://lucene.apache.org/core/old_versioned_docs/versions/3_0_0/scoring.html
来源：https://stackoverflow.com/questions/9829161/lucene-how-to-boost-some-specific-field