set hive.map.aggr=true; set hive.groupby.skewindata=false; set mapred.reduce.tasks=31; -- SORT_QUERY_RESULTS CREATE TABLE dest1(key STRING, c1 INT, c2 STRING) STORED AS TEXTFILE; EXPLAIN FROM src INSERT OVERWRITE TABLE dest1 SELECT substr(src.key,1,1), count(DISTINCT substr(src.value,5)), concat(substr(src.key,1,1),sum(substr(src.value,5))) GROUP BY substr(src.key,1,1); FROM src INSERT OVERWRITE TABLE dest1 SELECT substr(src.key,1,1), count(DISTINCT substr(src.value,5)), concat(substr(src.key,1,1),sum(substr(src.value,5))) GROUP BY substr(src.key,1,1); SELECT dest1.* FROM dest1;