Is {Filter}ing faster than {Query}ing in Lucene?

Question

While reading \"Lucene in Action 2nd edition\" I came across the description of Filter classes which are could be used for result filtering in Lucene. Lucene ha

Answer 1

I found this in http://wiki.apache.org/lucene-java/ImproveSearchingSpeed which seems to suggest to use filters rather than queries. Intuitively it makes more sense to me as they pretty much should do the same thing, the only difference being that filters are not used in the score.

Consider using filters. It can be much more efficient to restrict results to a part of the index using a cached bit set filter rather than using a query clause. This is especially true for restrictions that match a great number of documents of a large index. Filters are typically used to restrict the results to a category but could in many cases be used to replace any query clause. One difference between using a Query and a Filter is that the Query has an impact on the score while a Filter does not.