Lucene filters are a powerful tool for narrowing the scope of a query to some particular subset. However, filters work on predefined subsets. You must already know what it is that you are seeking.
Sometimes you need to dynamically identify subsets. For example, let's give our
App entity a
category property representing its genre:
... @Column @Field private String category; ...
When we perform a keyword search for apps, we might want to know which categories are represented in the results and how many results fall under each category. We might also want to know which price ranges were found. All of this information can help guide users in narrowing their queries more effectively.
The process of dynamically identifying ...