set hive.optimize.bucketmapjoin = true; set hive.optimize.bucketmapjoin.sortedmerge = true; 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 two bucketed and sorted tables CREATE TABLE test_table1 (key INT, value STRING) PARTITIONED BY (ds STRING) CLUSTERED BY (key) SORTED BY (key) INTO 16 BUCKETS; CREATE TABLE test_table2 (key INT, value STRING) PARTITIONED BY (ds STRING) CLUSTERED BY (key) SORTED BY (key) INTO 16 BUCKETS; FROM src INSERT OVERWRITE TABLE test_table1 PARTITION (ds = '1') SELECT *; -- Insert data into the bucketed table by selecting from another bucketed table -- This should be a map-only operation EXPLAIN INSERT OVERWRITE TABLE test_table2 PARTITION (ds = '1') SELECT a.key, a.value FROM test_table1 a WHERE a.ds = '1'; INSERT OVERWRITE TABLE test_table2 PARTITION (ds = '1') SELECT a.key, a.value FROM test_table1 a WHERE a.ds = '1'; select count(*) from test_table1 where ds = '1'; select count(*) from test_table1 where ds = '1' and hash(key) % 16 = 0; select count(*) from test_table1 where ds = '1' and hash(key) % 16 = 5; select count(*) from test_table1 where ds = '1' and hash(key) % 16 = 12; select count(*) from test_table1 tablesample (bucket 1 out of 16) s where ds = '1'; select count(*) from test_table1 tablesample (bucket 6 out of 16) s where ds = '1'; select count(*) from test_table1 tablesample (bucket 13 out of 16) s where ds = '1'; select count(*) from test_table2 where ds = '1'; select count(*) from test_table2 where ds = '1' and hash(key) % 16 = 0; select count(*) from test_table2 where ds = '1' and hash(key) % 16 = 5; select count(*) from test_table2 where ds = '1' and hash(key) % 16 = 12; select count(*) from test_table2 tablesample (bucket 1 out of 16) s where ds = '1'; select count(*) from test_table2 tablesample (bucket 6 out of 16) s where ds = '1'; select count(*) from test_table2 tablesample (bucket 13 out of 16) s where ds = '1';