[
https://issues.apache.org/jira/browse/FLINK-33365?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17784924#comment-17784924
]
david radley commented on FLINK-33365:
--------------------------------------
Testing against MariaDB I see:
select CAST(0 AS INT) as type from c;
+------+
| type |
+------+
| 0 |
| 0 |
+------+
It looks like this change from a filter to a cast is not logically equivalent.
> Missing filter condition in execution plan containing lookup join with mysql
> jdbc connector
> -------------------------------------------------------------------------------------------
>
> Key: FLINK-33365
> URL: https://issues.apache.org/jira/browse/FLINK-33365
> Project: Flink
> Issue Type: Bug
> Components: Connectors / JDBC
> Affects Versions: 1.18.0, 1.17.1
> Environment: Flink 1.17.1 & Flink 1.18.0 with
> flink-connector-jdbc-3.1.1-1.17.jar
> Reporter: macdoor615
> Assignee: david radley
> Priority: Critical
> Attachments: flink-connector-jdbc-3.0.0-1.16.png,
> flink-connector-jdbc-3.1.1-1.17.png
>
>
> create table in flink with sql-client.sh
> {code:java}
> CREATE TABLE default_catalog.default_database.a (
> ip string,
> proctime as proctime()
> )
> WITH (
> 'connector' = 'datagen'
> );{code}
> create table in mysql
> {code:java}
> create table b (
> ip varchar(20),
> type int
> ); {code}
>
> Flink 1.17.1/ 1.18.0 and *flink-connector-jdbc-3.1.1-1.17.jar*
> excute in sql-client.sh
> {code:java}
> explain SELECT * FROM default_catalog.default_database.a left join
> bnpmp_mysql_test.gem_tmp.b FOR SYSTEM_TIME AS OF a.proctime on b.type = 0 and
> a.ip = b.ip; {code}
> get the execution plan
> {code:java}
> ...
> == Optimized Execution Plan ==
> Calc(select=[ip, PROCTIME_MATERIALIZE(proctime) AS proctime, ip0, type])
> +- LookupJoin(table=[bnpmp_mysql_test.gem_tmp.b], joinType=[LeftOuterJoin],
> lookup=[ip=ip], select=[ip, proctime, ip, CAST(0 AS INTEGER) AS type, CAST(ip
> AS VARCHAR(2147483647)) AS ip0])
> +- Calc(select=[ip, PROCTIME() AS proctime])
> +- TableSourceScan(table=[[default_catalog, default_database, a]],
> fields=[ip]){code}
>
> excute same sql in sql-client with Flink 1.17.1/ 1.18.0 and
> *flink-connector-jdbc-3.0.0-1.16.jar*
> get the execution plan
> {code:java}
> ...
> == Optimized Execution Plan ==
> Calc(select=[ip, PROCTIME_MATERIALIZE(proctime) AS proctime, ip0, type])
> +- LookupJoin(table=[bnpmp_mysql_test.gem_tmp.b], joinType=[LeftOuterJoin],
> lookup=[type=0, ip=ip], where=[(type = 0)], select=[ip, proctime, ip, CAST(0
> AS INTEGER) AS type, CAST(ip AS VARCHAR(2147483647)) AS ip0])
> +- Calc(select=[ip, PROCTIME() AS proctime])
> +- TableSourceScan(table=[[default_catalog, default_database, a]],
> fields=[ip]) {code}
> with flink-connector-jdbc-3.1.1-1.17.jar, the condition is
> *lookup=[ip=ip]*
> with flink-connector-jdbc-3.0.0-1.16.jar , the condition is
> *lookup=[type=0, ip=ip], where=[(type = 0)]*
>
> In out real world production environment, this lead incorrect data output
>
>
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
