A ROS (Read Optimized Store) container is a set of rows stored in a particular group of files. ROS containers are created by operations like Moveout or COPY DIRECT. You can query the
STORAGE_CONTAINERS system table to see ROS containers. The ROS container layout can differ across nodes due to data variance. Segmentation can deliver more rows to one node than another. Two data loads could fit in the WOS on one node and spill on another.