Let's test what happens when you delete rows from a CCI with the following DELETE command. Before executing the command, you can check the estimated execution plan. Therefore, don't execute the following command yet:
DELETE FROM dbo.FactTest WHERE SaleKey >= 12000000;
The following screenshot shows the actual execution plan. You can see that, for the Columnstore Index Delete operator, row mode was used again:
Estimated execution plan for a DELETE
And here is a final check of the state of the rowgroups:
SELECT OBJECT_NAME(object_id) AS table_name, row_group_id, state, state_desc, total_rows, deleted_rows ...
