问题
I'm trying to do the following: I want to create a set of candidates by querying each field separately and then adding the top k matches to this set. After I'm done with that, I need to run another query on this candidate set. The way how I implemented it right now is using a QueryWrapperFilter with a BooleanQuery that matches the unique id field of each candidate document. However, this means I have to call IndexSearcher.doc().get("docId") for each candidate document before I can add it to my BooleanQuery, which is the major bottleneck. I'm only loading the docId field via MapFieldSelector("docId).
I wanted to create my own Filter class, but I can't use the internal Lucene doc ids directly, because they are specified per segment. Any thoughts on how to approach this?
回答1:
Instead of reading the stored docId, index the field (it probably already is) and use the FieldCache to retrieve docIds much faster. Then instead of using the docIds in a BooleanQuery, try using a TermsFilter or FieldCacheTermsFilter. The latter documentation describes the performance trade-offs.
来源：https://stackoverflow.com/questions/10627655/lucene-filter-with-docids