As per Lucene documentation there is not much difference between these 2 implementations and users should use the Open() method and Lucene choses the best implementation based on the system.
https://lucene.apache.org/core/9_7_0/core/org/apache/lucene/store/FSDirectory.html Is there any perf impact on choosing one of the options on a 64 bit linux system ? Do we have any comparison numbers? What is the advantage of using MMapDirectory when we already have a system buffer cache (on linux) for file access ? Thanks Ashwini
