Ping Lu created HIVE-13228:
------------------------------
Summary: when set hive.auto.convert.join and
hive.optimize.skewjoin to true, the SELECT query which contains 3-way join is
not properly executed
Key: HIVE-13228
URL: https://issues.apache.org/jira/browse/HIVE-13228
Project: Hive
Issue Type: Bug
Affects Versions: 2.0.0, 0.13.1
Environment: Hadoop2.4.0 Hive0.13.1/2.0.0
Reporter: Ping Lu
Assignee: Ping Lu
when set hive.auto.convert.join and hive.optimize.skewjoin to true, the SELECT
query which contains 3-way join(like the following Query1) is not properly
executed. According to hive execution logs, the query ran finished without any
errors, but didn’t return any results. If I set hive.optimize.skewjoin to
false, or set hive.auto.convert.join to false and hive.optimize.skewjoin to
true, the SELECT query can both execute properly and return correct results.
Steps to reproduce
Prepare:
create three test tables and load data
create table test1(col1 string,col2 string) row format delimited fields
terminated by "\t";
create table test2(col1 string,col2 string) row format delimited fields
terminated by "\t";
create table test3(col1 string,col2 string) row format delimited fields
terminated by "\t";
load data local inpath "test1" into table test1; //11870882 rows
load data local inpath "test2" into table test2; //11870882 rows
load data local inpath "test3" into table test3; //11870882 rows
Query1: SELECT query got wrong result
set hive.optimize.skewjoin = true;
set hive.auto.convert.join = true;
select
t1.col1
from
test1 t1
join
test2 t2
on t1.col1 = t2.col1
join
test3 t3
on t1.col2 = t3.col1
;
Query2: SELECT query got correct result
set hive.optimize.skewjoin = false;
set hive.auto.convert.join = true;
select
t1.col1
from
test1 t1
join
test2 t2
on t1.col1 = t2.col1
join
test3 t3
on t1.col2 = t3.col1
;
the execute plan for Query1 names explain1.txt .
the hive execution logs for Query1: SELECT statement names execution1.txt .
the execute plan for the Query2 names explain2.txt .
the hive execution logs for Query2 names execution2.txt .
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