--! qt:dataset:src | |
set hive.mapred.mode=nonstrict; | |
set hive.explain.user=false; | |
-- SORT_BEFORE_DIFF | |
-- union case: both subqueries are map-reduce jobs on same input, followed by reduce sink | |
explain | |
select count(1) FROM (select s1.key as key, s1.value as value from src s1 UNION ALL | |
select s2.key as key, s2.value as value from src s2) unionsrc; | |
select count(1) FROM (select s1.key as key, s1.value as value from src s1 UNION ALL | |
select s2.key as key, s2.value as value from src s2) unionsrc; |