[ 
https://issues.apache.org/jira/browse/HIVE-15327?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Jesus Camacho Rodriguez updated HIVE-15327:
-------------------------------------------
    Attachment: HIVE-15327.patch

> Outerjoin might produce wrong result depending on joinEmitInterval value
> ------------------------------------------------------------------------
>
>                 Key: HIVE-15327
>                 URL: https://issues.apache.org/jira/browse/HIVE-15327
>             Project: Hive
>          Issue Type: Bug
>          Components: Query Processor
>    Affects Versions: 1.3.0, 2.2.0
>            Reporter: Jesus Camacho Rodriguez
>            Assignee: Jesus Camacho Rodriguez
>            Priority: Critical
>         Attachments: HIVE-15327.patch
>
>
> If joinEmitInterval is smaller than the group size, outerjoins might produce 
> records with NULL appended values multiple times (once per group).
> HIVE-4689 targeted the same problem. However, the fix does not seem to cover 
> all cases (in particular, it will not apply to left outer joins with filter 
> conditions on the left input). The solution in HIVE-4689 was to disable 
> (override) joinEmitInterval value for those cases. This fix follows the same 
> approach.
> To reproduce the problem:
> {code}
> set hive.strict.checks.cartesian.product=false;
> set hive.join.emit.interval=1;
> CREATE TABLE test1 (key INT, value INT, col_1 STRING);
> INSERT INTO test1 VALUES (99, 0, 'Alice');
> INSERT INTO test1 VALUES (99, 2, 'Mat');
> INSERT INTO test1 VALUES (100, 1, 'Bob');
> INSERT INTO test1 VALUES (101, 2, 'Car');
> CREATE TABLE test2 (key INT, value INT, col_2 STRING);
> INSERT INTO test2 VALUES (102, 2, 'Del');
> INSERT INTO test2 VALUES (103, 2, 'Ema');
> INSERT INTO test2 VALUES (104, 3, 'Fli');
> -- Equi-condition and condition on one input (left outer join)
> SELECT *
> FROM test1 LEFT OUTER JOIN test2
> ON (test1.value=test2.value AND test1.key between 100 and 102)
> LIMIT 10;
> -- Condition on one input (left outer join)
> SELECT *
> FROM test1 LEFT OUTER JOIN test2
> ON (test1.key between 100 and 102)
> LIMIT 10;
> {code}
> For the *first* query, current (incorrect) result is:
> {noformat}
>  99     0       Alice   NULL    NULL    NULL
>  100    1       Bob     NULL    NULL    NULL
>  101    2       Car     103     2       Ema
>  99     2       Mat     NULL    NULL    NULL
>  101    2       Car     102     2       Del
>  99     2       Mat     NULL    NULL    NULL
> {noformat}
> Expected (correct) result is:
> {noformat}
>  99     0       Alice   NULL    NULL    NULL
>  100    1       Bob     NULL    NULL    NULL
>  101    2       Car     103     2       Ema
>  101    2       Car     102     2       Del
>  99     2       Mat     NULL    NULL    NULL
> {noformat}
> For the *second* query, current (incorrect) result is:
> {noformat}
>  101    2       Car     104     3       Fli
>  100    1       Bob     104     3       Fli
>  99     2       Mat     NULL    NULL    NULL
>  99     0       Alice   NULL    NULL    NULL
>  101    2       Car     103     2       Ema
>  100    1       Bob     103     2       Ema
>  99     2       Mat     NULL    NULL    NULL
>  99     0       Alice   NULL    NULL    NULL
>  101    2       Car     102     2       Del
>  100    1       Bob     102     2       Del
> {noformat}
> Expected (correct) result is:
> {noformat}
>  101    2       Car     104     3       Fli
>  101    2       Car     103     2       Ema
>  101    2       Car     102     2       Del
>  100    1       Bob     104     3       Fli
>  100    1       Bob     103     2       Ema
>  100    1       Bob     102     2       Del
>  99     2       Mat     NULL    NULL    NULL
>  99     0       Alice   NULL    NULL    NULL
> {noformat}



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Reply via email to