I came across this type when I checked this blog: http://blog.trifork.com/2011/10/27/introducing-lucene-index-doc-values/ The blog mentions that the IndexDocValues are created as sorting types indexed specifically for the purpose and reduce the overhead created by the FieldCache.
I could not locate this class in the Lucene 4.7.2 hierarchy. Is this replaced by somewhat similar SortedDocValuesField? And are there any benchmarks that show the memory and sorting time using this field as opposed to sorting on a regular StringField. ----------------------- Thanks n Regards, Sandeep Ramesh Khanzode