"There are some limitations in the "order by" clause. In the strict mode (i.e., hive.mapred.mode=strict), the order by clause has to be followed by a "limit" clause."
"The reason is that in order to impose total order of all results, there has to be one reducer to sort the final output. If the number of rows in the output is too large, the single reducer could take a very long time to finish." [t]2020-09-19 20:44:20