Niko Neugebauer does some investigation into where, exactly, memory-optimized columnstore data goes:
This is a rather simple blog post that is dedicated to the theme of the In-Memory Columnstore Indexes location. This has been a constant topic of discussion over a long period of time, even during the public events – and there is a need to clear out this topic.
I have assumed that the In-Memory Columnstore structures (Segments, Dictionaries, …) are located in the In-Memory, but there have been voices that I greatly respect, pointing that actually the Columnstore Object Pool is the exact location of any Columnstore structures, and there is nothing better than to take this feature for a ride and see what the SQL Server engine is actually doing.
Niko shows off a couple of useful DMVs along the way, too.