073eee46_n_Memory_Columnar_Store__IMCS___Recommendations
[Parameter name] imcs.cache_size(*) [Description] Size of IMCS disk cache (in pages) [Default value] 256*1024 [Recommendations] 
Total size in bytes used by cache is imcs.cache_size*imcs.page_size. With default values of parameters it is 1Gb. It should be smaller than imcs.shmem_size. See more about choosing optimal setting for this parameter in section Scaling beyond physical memory.
In-Memory Columnar Store (IMCS)
Recommendations