[
https://issues.apache.org/jira/browse/DRILL-4477?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15183749#comment-15183749
]
Victoria Markman commented on DRILL-4477:
-----------------------------------------
Same in 1.4.0:
{code}
0: jdbc:drill:drillbit=localhost> select * from sys.version;
+----------+-------------------------------------------+-------------------------------------------------------------------------+----------------------------+--------------+----------------------------+
| version | commit_id |
commit_message | commit_time |
build_email | build_time |
+----------+-------------------------------------------+-------------------------------------------------------------------------+----------------------------+--------------+----------------------------+
| 1.4.0 | 556d9c5dbf4b0f776b57f0d39d07111ccc0d2e7b | MD-649: do the cost
adjustment for $SUM0 only when LIMIT 0 is present. | 07.01.2016 @ 18:19:31 UTC
| Unknown | 07.01.2016 @ 19:52:20 UTC |
+----------+-------------------------------------------+-------------------------------------------------------------------------+----------------------------+--------------+----------------------------+
1 row selected (1.082 seconds)
0: jdbc:drill:drillbit=localhost> select * from (select t1.a, t1.b, t1.c, t2.a,
t2.b, t2.c from `tt1.json` t1, `tt2.json` t2 where t1.c = t2.c);
+----+----+----+-----+-----+-----+
| a | b | c | a0 | b0 | c0 |
+----+----+----+-----+-----+-----+
| a | b | 1 | a | b | 1 |
+----+----+----+-----+-----+-----+
1 row selected (2.005 seconds)
{code}
> Wrong Plan (potentially wrong result) if wrapping a query with SELECT * FROM
> ----------------------------------------------------------------------------
>
> Key: DRILL-4477
> URL: https://issues.apache.org/jira/browse/DRILL-4477
> Project: Apache Drill
> Issue Type: Bug
> Components: Query Planning & Optimization
> Reporter: Sean Hsuan-Yi Chu
> Priority: Blocker
> Fix For: 1.6.0
>
> Attachments: t1.json, t2.json
>
>
> For example, a query
> {code}
> select * from (select s.name, v.name, v.registration from
> cp.`tpch/region.parquet` s left outer join cp.`tpch/nation.parquet` v
> on (s.name = v.name)
> where s.age < 30) t
> {code}
> gives a plan as below:
> {code}
> +------+------+
> | text | json |
> +------+------+
> | 00-00 Screen
> 00-01 Project(name=[$0], name0=[$1], registration=[$2])
> 00-02 Project(name=[$0], name0=[$0], registration=[$3])
> 00-03 Project(name=[$2], age=[$3], name0=[$0], registration=[$1])
> 00-04 HashJoin(condition=[=($2, $0)], joinType=[right])
> 00-06 Scan(groupscan=[ParquetGroupScan
> [entries=[ReadEntryWithPath [path=classpath:/tpch/nation.parquet]],
> selectionRoot=classpath:/tpch/nation.parquet, numFiles=1,
> usedMetadataFile=false, columns=[`name`, `registration`]]])
> 00-05 Project(name0=[$0], age=[$1])
> 00-07 SelectionVectorRemover
> 00-08 Filter(condition=[<($1, 30)])
> 00-09 Scan(groupscan=[ParquetGroupScan
> [entries=[ReadEntryWithPath [path=classpath:/tpch/region.parquet]],
> selectionRoot=classpath:/tpch/region.parquet, numFiles=1,
> usedMetadataFile=false, columns=[`name`, `age`]]])
> {code}
> In the line 00-02, both name and name0 point at the same incoming column
> (probably due to the JOIN CONDITION).
> However. the fact that these two are the JOIN condition does not make a case
> that they must be equal since implicit casting might be invoked to perform
> the JOIN condition.
> Interestingly, if the SELECT * FROM wrapper is removed, this bug won't be
> exposed:
> {code}
> select s.name, v.name, v.registration from cp.`tpch/region.parquet` s left
> outer join cp.`tpch/nation.parquet` v on (s.name = v.name)
> where s.age < 30
> {code}
> gives
> {code}
> 00-00 Screen
> 00-01 Project(name=[$0], name0=[$1], registration=[$2])
> 00-02 Project(name=[$2], name0=[$0], registration=[$1])
> 00-03 HashJoin(condition=[=($2, $0)], joinType=[right])
> 00-05 Scan(groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath
> [path=classpath:/tpch/nation.parquet]],
> selectionRoot=classpath:/tpch/nation.parquet, numFiles=1,
> usedMetadataFile=false, columns=[`name`, `registration`]]])
> 00-04 Project(name0=[$0])
> 00-06 Project(name=[$0])
> 00-07 SelectionVectorRemover
> 00-08 Filter(condition=[<($1, 30)])
> 00-09 Scan(groupscan=[ParquetGroupScan
> [entries=[ReadEntryWithPath [path=classpath:/tpch/region.parquet]],
> selectionRoot=classpath:/tpch/region.parquet, numFiles=1,
> usedMetadataFile=false, columns=[`name`, `age`]]])
> {code}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
