073eee46_n_Memory_Columnar_Store__IMCS___Recommendations
[Parameter name] imcs.substitute_nulls [Description] Substitutes NULLs with 0 while loading data in columnar store [Default value] false [Recommendations] 
By default attempt to insert NULL value will cause an error. When value of this option is set to true, IMCS doesn't report an error and stores zero instead of NULL.
In-Memory Columnar Store (IMCS)
Recommendations