| set hive.new.job.grouping.set.cardinality=2; | |
| set hive.map.aggr=true; | |
| set hive.groupby.skewindata=true; | |
| CREATE TABLE T1(a STRING, b STRING, c STRING) ROW FORMAT DELIMITED FIELDS TERMINATED BY ' ' STORED AS TEXTFILE; | |
| -- Since 4 grouping sets would be generated for the query below, an additional MR job should be created | |
| -- This is not allowed with map-side aggregation and skew | |
| SELECT a, b, count(1) from T1 group by a, b with cube; | |