I see the NativeUnixDirectory in the document which "A Directory <https://lucene.apache.org/core/6_5_0/core/org/apache/lucene/store/Directory.html?is-external=true> implementation for all Unixes that uses DIRECT I/O to bypass OS level IO caching during merging. For all other cases (searching, writing) we delegate to the provided Directory instance" I wonder how to use this directory while merging? Is there any possible to use NativeUnixDirectory only in merging, and others are FSDirectory?
