| set hive.optimize.bucketmapjoin = true; |
| set hive.optimize.bucketmapjoin.sortedmerge = true; |
| set hive.input.format = org.apache.hadoop.hive.ql.io.BucketizedHiveInputFormat; |
| set hive.enforce.bucketing=true; |
| set hive.enforce.sorting=true; |
| set hive.exec.reducers.max = 1; |
| set hive.merge.mapfiles=false; |
| set hive.merge.mapredfiles=false; |
| |
| -- Create bucketed and sorted tables |
| CREATE TABLE test_table1 (key INT, value STRING) CLUSTERED BY (key) SORTED BY (key) INTO 2 BUCKETS; |
| CREATE TABLE test_table2 (key INT, value STRING) CLUSTERED BY (key) SORTED BY (key) INTO 2 BUCKETS; |
| |
| FROM src |
| INSERT OVERWRITE TABLE test_table1 SELECT * |
| INSERT OVERWRITE TABLE test_table2 SELECT *; |
| |
| -- Mapjoin followed by a aggregation should be performed in a single MR job |
| EXPLAIN |
| SELECT /*+mapjoin(b)*/ count(*) FROM test_table1 a JOIN test_table2 b ON a.key = b.key; |
| SELECT /*+mapjoin(b)*/ count(*) FROM test_table1 a JOIN test_table2 b ON a.key = b.key; |