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Posted to dev@hive.apache.org by "Rajkumar Singh (Jira)" <ji...@apache.org> on 2020/05/13 05:00:09 UTC
[jira] [Created] (HIVE-23457) Hive Incorrect result with subquery
while optimizer misses the aggregation stage
Rajkumar Singh created HIVE-23457:
-------------------------------------
Summary: Hive Incorrect result with subquery while optimizer misses the aggregation stage
Key: HIVE-23457
URL: https://issues.apache.org/jira/browse/HIVE-23457
Project: Hive
Issue Type: Bug
Components: Hive
Affects Versions: 3.2.0
Reporter: Rajkumar Singh
Steps to Repro:
{code:java}
create table abc (id int);
insert into table abc values (1),(2),(3),(4),(5),(6);
select * from abc order by id desc
6
5
4
3
2
1
select `id` from (select * from abc order by id desc ) as tmp;
1
2
3
4
5
6
{code}
looking at the query plan it seems while using the subquery optimizer missed the aggregation stage, I cant see any reduce stage.
{code:java}
set hive.query.results.cache.enabled=false;
explain select * from abc order by id desc;
+----------------------------------------------------+
| Explain |
+----------------------------------------------------+
| Plan optimized by CBO. |
| |
| Vertex dependency in root stage |
| Reducer 2 <- Map 1 (SIMPLE_EDGE) |
| |
| Stage-0 |
| Fetch Operator |
| limit:-1 |
| Stage-1 |
| Reducer 2 vectorized |
| File Output Operator [FS_8] |
| Select Operator [SEL_7] (rows=6 width=4) |
| Output:["_col0"] |
| <-Map 1 [SIMPLE_EDGE] vectorized |
| SHUFFLE [RS_6] |
| Select Operator [SEL_5] (rows=6 width=4) |
| Output:["_col0"] |
| TableScan [TS_0] (rows=6 width=4) |
| default@abc,abc, ACID table,Tbl:COMPLETE,Col:COMPLETE,Output:["id"] |
| |
+----------------------------------------------------+
explain select `id` from (select * from abc order by id desc ) as tmp;
+------------------------------+
| Explain |
+------------------------------+
| Plan optimized by CBO. |
| |
| Stage-0 |
| Fetch Operator |
| limit:-1 |
| Select Operator [SEL_1] |
| Output:["_col0"] |
| TableScan [TS_0] |
| Output:["id"] |
| |
+------------------------------+
{code}
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