Lucene in Action

... (t) in the document (d). idf(t) Inverse document frequency of the term. boost(t.field in d) Field boost ... . The default value of field boosts, logically, is 1.0. During indexing, a Document can be assigned a boost, too. A Document boost factor implicitly sets the starting field boost of all fields to the specified ... of the field boost factor. It's possible to add the same named field to a Document multiple times, and in such situations the field boost is computed as all the boosts specified for that field and document... [Full sample chapter]

...Not all Documents and Fields are created equal--or at least you can make sure that's the case by selectively boosting Documents or Fields. Imagine you have to write an application that indexes ... their boost factor to 0.1. Just as you can boost Documents, you can also boost individual Fields. When you boost a Document, Lucene internally uses the same boost factor to boost each of its Fields ... feature that many applications can work very well without. Document and Field boosting comes...

... to a Lucene document: doc.add(Field.UnStored("fullcontents", theHolder.getFullContents())); doc.add(Field ... that we want to place on fields or the document itself. It turns out that we end up with the boosters shown in table 10.8. Table 10.8 TheServerSide field boosts Boost Description Title A title should have more ... , isn't it? We boost a document if it is new, and the boost decreases as time goes on. The date boost ... . Now we will discuss the index building process and the design choices that we made. What fields should...

Pages 38 and 39, boosts should be set as flots: doc.setBoost(1.5f); doc.setBoost(0.1f); subjectField.setBoost(1.2f); [Permalink]