set hive.stats.autogather=false;
set hive.optimize.union.remove=true;
set hive.mapred.supports.subdirectories=true;
set hive.exec.dynamic.partition=true;
set hive.exec.dynamic.partition.mode=nonstrict;
set hive.merge.sparkfiles=false;
set hive.merge.mapfiles=false;
set hive.merge.mapredfiles=false;
set mapred.input.dir.recursive=true;

-- This is to test the union->selectstar->filesink optimization
-- Union of 2 map-reduce subqueries is performed followed by select star and a file sink
-- There is no need to write the temporary results of the sub-queries, and then read them 
-- again to process the union. The union can be removed completely.
-- It does not matter, whether the output is merged or not. In this case, merging is turned
-- off
-- INCLUDE_HADOOP_MAJOR_VERSIONS(0.23)
-- Since this test creates sub-directories for the output table outputTbl1, it might be easier
-- to run the test only on hadoop 23

create table inputTbl1(key string, val string) stored as textfile;
create table outputTbl1(key string, `values` bigint) partitioned by (ds string) stored as textfile;
create table outputTbl2(key string, `values` bigint) partitioned by (ds string) stored as textfile;
create table outputTbl3(key string, `values` bigint) partitioned by (ds string,hr string) stored as textfile;

load data local inpath '../../data/files/T1.txt' into table inputTbl1;

explain
insert overwrite table outputTbl1 partition(ds='2004')
SELECT *
FROM (
  SELECT key, count(1) as `values` from inputTbl1 group by key
  UNION ALL
  SELECT key, count(1) as `values` from inputTbl1 group by key
) a;

insert overwrite table outputTbl1 partition(ds='2004')
SELECT *
FROM (
  SELECT key, count(1) as `values` from inputTbl1 group by key
  UNION ALL
  SELECT key, count(1) as `values` from inputTbl1 group by key
) a;

desc formatted outputTbl1 partition(ds='2004');

set hive.input.format=org.apache.hadoop.hive.ql.io.HiveInputFormat;
select * from outputTbl1 order by key, `values`;

explain 
insert overwrite table outputTbl2 partition(ds)
SELECT *
FROM (
  select * from (SELECT key, value, ds from srcpart where ds='2008-04-08' limit 500)a
  UNION ALL
  select * from (SELECT key, value, ds from srcpart where ds='2008-04-08' limit 500)b
) a;

insert overwrite table outputTbl2 partition(ds)
SELECT *
FROM (
  select * from (SELECT key, value, ds from srcpart where ds='2008-04-08' limit 500)a
  UNION ALL
  select * from (SELECT key, value, ds from srcpart where ds='2008-04-08' limit 500)b
) a;

show partitions outputTbl2;
desc formatted outputTbl2 partition(ds='2008-04-08');

explain insert overwrite table outputTbl3 partition(ds, hr)
SELECT *
FROM (
  select * from (SELECT key, value, ds, hr from srcpart where ds='2008-04-08' limit 1000)a
  UNION ALL
  select * from (SELECT key, value, ds, hr from srcpart where ds='2008-04-08' limit 1000)b
) a;

insert overwrite table outputTbl3 partition(ds, hr)
SELECT *
FROM (
  select * from (SELECT key, value, ds, hr from srcpart where ds='2008-04-08' limit 1000)a
  UNION ALL
  select * from (SELECT key, value, ds, hr from srcpart where ds='2008-04-08' limit 1000)b
) a;

show partitions outputTbl3;
desc formatted outputTbl3 partition(ds='2008-04-08', hr='11');