073eee46_n_Memory_Columnar_Store__IMCS___Recommendations
[Parameter name] imcs.flush_file(*) [Description] Flush changes to the file during commit [Default value] true [Recommendations] 
Write dirty pages to the disk during commit. Pages are written in offset increasing order, so disk writes are more or less sequential minimizing disk head movements. That is why it can be faster than random writes of dirty pages thrown away by LRU replacement algorithm. But it can increase number of writes, especially in case of short transactions (for example if triggers are used to propagate updates to IMCS).
In-Memory Columnar Store (IMCS)
Recommendations