Chiran Ravani created HIVE-23265:
------------------------------------

             Summary: Duplicate rowsets are returned with Limit and Offset ste
                 Key: HIVE-23265
                 URL: https://issues.apache.org/jira/browse/HIVE-23265
             Project: Hive
          Issue Type: Bug
          Components: HiveServer2, Vectorization
    Affects Versions: 3.1.2, 3.1.0
            Reporter: Chiran Ravani
         Attachments: 000000_0

We have a query which produces duplicate results even when there is no 
duplicate records in underlying tables.

Sample Query
{code:java}
select * from orderdatatest_ext order by col1 limit 1000,50
{code}

The problem appears when order by clause is used with col1 having non-unique 
rows. Apparently the duplicates are being produced during reducer phase of the 
query.
set hive.vectorized.execution.reduce.enabled=false does not cause the problem.

Data in table is as follows.
{code:java}
1,1
1,2
1,3
.
.
1,1500
{code}

Results with hive.vectorized.execution.reduce.enabled=true

{code:java}
+-------------------------+-------------------------+
| orderdatatest_ext.col1  | orderdatatest_ext.col2  |
+-------------------------+-------------------------+
| 1                       | 1001                    |
| 1                       | 1002                    |
| 1                       | 1003                    |
| 1                       | 1004                    |
| 1                       | 1005                    |
| 1                       | 1006                    |
| 1                       | 1007                    |
| 1                       | 1008                    |
| 1                       | 1009                    |
| 1                       | 1010                    |
| 1                       | 1011                    |
| 1                       | 1012                    |
| 1                       | 1013                    |
| 1                       | 1014                    |
| 1                       | 1015                    |
| 1                       | 1016                    |
| 1                       | 1017                    |
| 1                       | 1018                    |
| 1                       | 1019                    |
| 1                       | 1020                    |
| 1                       | 1021                    |
| 1                       | 1022                    |
| 1                       | 1023                    |
| 1                       | 1024                    |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
| 1                       | 1                       |
+-------------------------+-------------------------+
{code}

Results with hive.vectorized.execution.reduce.enabled=false

{code:java}
+-------------------------+-------------------------+
| orderdatatest_ext.col1  | orderdatatest_ext.col2  |
+-------------------------+-------------------------+
| 1                       | 1001                    |
| 1                       | 1002                    |
| 1                       | 1003                    |
| 1                       | 1004                    |
| 1                       | 1005                    |
| 1                       | 1006                    |
| 1                       | 1007                    |
| 1                       | 1008                    |
| 1                       | 1009                    |
| 1                       | 1010                    |
| 1                       | 1011                    |
| 1                       | 1012                    |
| 1                       | 1013                    |
| 1                       | 1014                    |
| 1                       | 1015                    |
| 1                       | 1016                    |
| 1                       | 1017                    |
| 1                       | 1018                    |
| 1                       | 1019                    |
| 1                       | 1020                    |
| 1                       | 1021                    |
| 1                       | 1022                    |
| 1                       | 1023                    |
| 1                       | 1024                    |
| 1                       | 1025                    |
| 1                       | 1026                    |
| 1                       | 1027                    |
| 1                       | 1028                    |
| 1                       | 1029                    |
| 1                       | 1030                    |
| 1                       | 1031                    |
| 1                       | 1032                    |
| 1                       | 1033                    |
| 1                       | 1034                    |
| 1                       | 1035                    |
| 1                       | 1036                    |
| 1                       | 1037                    |
| 1                       | 1038                    |
| 1                       | 1039                    |
| 1                       | 1040                    |
| 1                       | 1041                    |
| 1                       | 1042                    |
| 1                       | 1043                    |
| 1                       | 1044                    |
| 1                       | 1045                    |
| 1                       | 1046                    |
| 1                       | 1047                    |
| 1                       | 1048                    |
| 1                       | 1049                    |
| 1                       | 1050                    |
+-------------------------+-------------------------+
{code}

Table DDL
{code:java}
CREATE EXTERNAL TABLE  orderdatatest_ext (col1 int, col2 int) stored as orc
{code}

Attached sample ORC file.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)

Reply via email to