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Posted to dev@flink.apache.org by "Shuo Cheng (Jira)" <ji...@apache.org> on 2021/03/31 07:31:00 UTC
[jira] [Created] (FLINK-22063) Lookup Join outputs wrong results
for some scenario
Shuo Cheng created FLINK-22063:
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Summary: Lookup Join outputs wrong results for some scenario
Key: FLINK-22063
URL: https://issues.apache.org/jira/browse/FLINK-22063
Project: Flink
Issue Type: New Feature
Components: Table SQL / API
Affects Versions: 1.12.2
Reporter: Shuo Cheng
Reproduce the bug as following:
In LookupJoinITCase, given the sql
{code:sql}
SELECT
T.id, T.len, D.id, T.content, D.name
FROM src AS T JOIN user_table for system_time as of T.proctime AS D
ON T.id = D.id and cast(T.len as bigint) = D.id
{code}
the following execution plan is generated:
{code:java}
LegacySink(name=[DataStreamTableSink], fields=[id, len, id0, content, name])
+- Calc(select=[id, len, id0, content, name])
+- LookupJoin(table=[**], joinType=[InnerJoin], async=[false], lookup=[id=len0], select=[id, len, content, len0, id, name])
+- Calc(select=[id, len, content, CAST(len) AS len0])
+- TableSourceScan(table=[[**]], fields=[id, len, content])
{code}
As we can see, the condition `T.id = D.id` is lost, so a wrong result may be produced.
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