/tags/release-0.0.0-rc0/hive/external/ql/src/test/queries/clientpositive/union11.q

 1set hive.map.aggr = true;
 2
 3-- union case: all subqueries are a map-reduce jobs, 3 way union, same input for all sub-queries, followed by reducesink
 4
 5explain 
 6  select unionsrc.key, count(1) FROM (select 'tst1' as key, count(1) as value from src s1
 7                                        UNION  ALL  
 8                                            select 'tst2' as key, count(1) as value from src s2
 9                                        UNION ALL
10                                            select 'tst3' as key, count(1) as value from src s3) unionsrc group by unionsrc.key;
11
12
13  select unionsrc.key, count(1) FROM (select 'tst1' as key, count(1) as value from src s1
14                                        UNION  ALL  
15                                            select 'tst2' as key, count(1) as value from src s2
16                                        UNION ALL
17                                            select 'tst3' as key, count(1) as value from src s3) unionsrc group by unionsrc.key;
18
19
20