Hi, I would like to replace MonetDB' sorting algorithms (timsort/quicksort) with my own. As the first step, I commented all content of function *do_sort()* in gdk_batop.c to disable the sorting functionality. Then I re-build the monetdb (with no error) and type a SQL statement with ORDER-BY clause in mclient interface: "select o_orderkey, o_custkey, o_orderstatus from orders order by o_custkey limit 10;" I was expecting to see the dis-ordered result. However, it turns out that the result is still ordered by o_custkey. I am confused about the result. Did I miss something? Any help would be great. Best regards, John