[jira] [Resolved] (TAJO-926) Join condition including column references of a row-preserving table in left outer join causes incorrect result

["Hyunsik Choi (JIRA)" <ji...@apache.org>]

     [ https://issues.apache.org/jira/browse/TAJO-926?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Hyunsik Choi resolved TAJO-926.
-------------------------------

    Resolution: Fixed

committed it to master branch.

> Join condition including column references of a row-preserving table in left outer join causes incorrect result
> ---------------------------------------------------------------------------------------------------------------
>
>                 Key: TAJO-926
>                 URL: https://issues.apache.org/jira/browse/TAJO-926
>             Project: Tajo
>          Issue Type: Bug
>          Components: physical operator, planner/optimizer
>            Reporter: Hyunsik Choi
>            Assignee: Hyunsik Choi
>             Fix For: 0.9.0
>
>
> This patch fixes two bugs.
> One is wrong projection push down (PPD). See the example, reproducing the bug:
> {noformat}
> select
>   r_name,
>   r_regionkey,
>   n_name,
>   n_regionkey
> from
>   region left outer join nation on n_regionkey = r_regionkey and r_name in ('AMERICA', 'ASIA')
> order by r_name;
> {noformat}
> The above query includes one left outer join (LOJ) and one join filter. Since this join filter {{R_NAME in ('AMERICA', 'ASIA')}} includes column references corresponding to the row preserved table {{region}}, the join filter is placed on the LOJ operator. It only results in the sub expression push down of RowConstantEval and replaces right expression of IN predicate by FieldEval. But, we assume that the RHS of InEval is always RowConstantEval. This is the main clause of this bug.
> {noformat}
> 2014-07-09 16:39:37,527 ERROR: org.apache.tajo.worker.Task (run(395)) - org.apache.tajo.engine.eval.FieldEval cannot be cast to org.apache.tajo.engine.eval.RowConstantEval
> java.lang.ClassCastException: org.apache.tajo.engine.eval.FieldEval cannot be cast to org.apache.tajo.engine.eval.RowConstantEval
> 	at org.apache.tajo.engine.eval.InEval.eval(InEval.java:62)
> 	at org.apache.tajo.engine.eval.BinaryEval.eval(BinaryEval.java:104)
> 	at org.apache.tajo.engine.planner.physical.NLLeftOuterJoinExec.next(NLLeftOuterJoinExec.java:109)
> 	at org.apache.tajo.engine.planner.physical.ExternalSortExec.sortAndStoreAllChunks(ExternalSortExec.java:201)
> 	at org.apache.tajo.engine.planner.physical.ExternalSortExec.next(ExternalSortExec.java:278)
> 	at org.apache.tajo.engine.planner.physical.RangeShuffleFileWriteExec.next(RangeShuffleFileWriteExec.java:99)
> 	at org.apache.tajo.worker.Task.run(Task.java:388)
> 	at org.apache.tajo.worker.TaskRunner$1.run(TaskRunner.java:406)
> 	at java.lang.Thread.run(Thread.java:744)
> 2014-07-09 16:39:37,528 INFO: org.apache.tajo.worker.TaskAttemptContext (setState(115)) - Query status of ta_1404891573341_0004_000003_000000_02 is changed to TA_FAILED
> 2014-07-09 16:39:37,529 INFO: org.apache.tajo.worker.Task (run(452)) - Worker's task counter - total:3, succeeded: 0, killed: 3, failed: 3
> {noformat}
> The second bug is that HashLeftOuterJoin results in wrong result when it has join filter corresponding to row preserved table like the above example query. 
> In order to fix this bug, we have to skip the right iterator of hash table when if the joined tuple is filtered.
> Expected:
> {noformat}
> r_name,r_regionkey,n_name,n_regionkey
> -------------------------------
> AFRICA,0,null,null
> AMERICA,1,ARGENTINA,1
> AMERICA,1,BRAZIL,1
> AMERICA,1,CANADA,1
> AMERICA,1,PERU,1
> AMERICA,1,UNITED STATES,1
> ASIA,2,INDIA,2
> ASIA,2,INDONESIA,2
> ASIA,2,JAPAN,2
> ASIA,2,CHINA,2
> ASIA,2,VIETNAM,2
> EUROPE,3,null,null
> MIDDLE EAST,4,null,null
> {noformat}
> Actual result:
> {noformat}
> r_name,r_regionkey,n_name,n_regionkey
> -------------------------------
> AFRICA,0,null,null
> AFRICA,0,null,null
> AFRICA,0,null,null
> AFRICA,0,null,null
> AFRICA,0,null,null
> AMERICA,1,ARGENTINA,1
> AMERICA,1,BRAZIL,1
> AMERICA,1,CANADA,1
> AMERICA,1,PERU,1
> AMERICA,1,UNITED STATES,1
> ASIA,2,INDIA,2
> ASIA,2,INDONESIA,2
> ASIA,2,JAPAN,2
> ASIA,2,CHINA,2
> ASIA,2,VIETNAM,2
> EUROPE,3,null,null
> EUROPE,3,null,null
> EUROPE,3,null,null
> EUROPE,3,null,null
> EUROPE,3,null,null
> MIDDLE EAST,4,null,null
> MIDDLE EAST,4,null,null
> MIDDLE EAST,4,null,null
> MIDDLE EAST,4,null,null
> MIDDLE EAST,4,null,null
> {noformat}



--
This message was sent by Atlassian JIRA
(v6.2#6252)