ql/src/test/queries/clientpositive/explain_rearrange.q

--! qt:dataset:src1
set hive.mapred.mode=nonstrict;
-- query from auto_sortmerge_join_9.q

CREATE TABLE tbl1_n9(key int, value string) CLUSTERED BY (key) SORTED BY (key) INTO 2 BUCKETS;
CREATE TABLE tbl2_n8(key int, value string) CLUSTERED BY (key) SORTED BY (key) INTO 2 BUCKETS;

set hive.auto.convert.join=true;
set hive.optimize.bucketmapjoin = true;
set hive.optimize.bucketmapjoin.sortedmerge = true;
set hive.auto.convert.sortmerge.join=true;
set hive.auto.convert.sortmerge.join.to.mapjoin=false;

set hive.explain.dependency.append.tasktype=true;

-- default behavior

explain
select src1.key, src1.cnt1, src2.cnt1 from
(
  select key, count(*) as cnt1 from
  (
    select a.key as key, a.value as val1, b.value as val2 from tbl1_n9 a join tbl2_n8 b on a.key = b.key
  ) subq1 group by key
) src1
join
(
  select key, count(*) as cnt1 from
  (
    select a.key as key, a.value as val1, b.value as val2 from tbl1_n9 a join tbl2_n8 b on a.key = b.key
  ) subq2 group by key
) src2
on src1.key = src2.key
order by src1.key, src1.cnt1, src2.cnt1;

set hive.stageid.rearrange=IDONLY;

-- changes id only

explain
select src1.key, src1.cnt1, src2.cnt1 from
(
  select key, count(*) as cnt1 from
  (
    select a.key as key, a.value as val1, b.value as val2 from tbl1_n9 a join tbl2_n8 b on a.key = b.key
  ) subq1 group by key
) src1
join
(
  select key, count(*) as cnt1 from
  (
    select a.key as key, a.value as val1, b.value as val2 from tbl1_n9 a join tbl2_n8 b on a.key = b.key
  ) subq2 group by key
) src2
on src1.key = src2.key
order by src1.key, src1.cnt1, src2.cnt1;

set hive.stageid.rearrange=TRAVERSE;

-- assign ids in traverse order

explain
select src1.key, src1.cnt1, src2.cnt1 from
(
  select key, count(*) as cnt1 from
  (
    select a.key as key, a.value as val1, b.value as val2 from tbl1_n9 a join tbl2_n8 b on a.key = b.key
  ) subq1 group by key
) src1
join
(
  select key, count(*) as cnt1 from
  (
    select a.key as key, a.value as val1, b.value as val2 from tbl1_n9 a join tbl2_n8 b on a.key = b.key
  ) subq2 group by key
) src2
on src1.key = src2.key
order by src1.key, src1.cnt1, src2.cnt1;

set hive.stageid.rearrange=EXECUTION;

-- assign ids in execution order

explain
select src1.key, src1.cnt1, src2.cnt1 from
(
  select key, count(*) as cnt1 from
  (
    select a.key as key, a.value as val1, b.value as val2 from tbl1_n9 a join tbl2_n8 b on a.key = b.key
  ) subq1 group by key
) src1
join
(
  select key, count(*) as cnt1 from
  (
    select a.key as key, a.value as val1, b.value as val2 from tbl1_n9 a join tbl2_n8 b on a.key = b.key
  ) subq2 group by key
) src2
on src1.key = src2.key
order by src1.key, src1.cnt1, src2.cnt1;