Hi, Recently, I am studying how to store and index using Solr. I want to do facet.prefix search. With whitespace tokenizer, "Where are you" will be splited into three words and indexed. If I search facet.prefix="where are", no result will be returned. I google and found NGramFilterFactory can help me. But when I apply this filter factory, I found the result is "w, h, e, ..., wh, ..", which split the sentence by character, not by token word. I use the parameters maxGramSize and minGramSize, set to 1 and 3. Does the NGramFilterFactory work right? Should I add some other parameters? Is there some other filter factories which can help me? Thanks!