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https://issues.apache.org/jira/browse/FLINK-35318?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17848071#comment-17848071
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Jane Chan commented on FLINK-35318:
-----------------------------------
Thanks for your contribution [~linshangquan], I'll take a look as quickly as I
can.
> incorrect timezone handling for TIMESTAMP_WITH_LOCAL_TIME_ZONE type during
> predicate pushdown
> ---------------------------------------------------------------------------------------------
>
> Key: FLINK-35318
> URL: https://issues.apache.org/jira/browse/FLINK-35318
> Project: Flink
> Issue Type: Bug
> Components: Table SQL / API
> Affects Versions: 1.18.1
> Environment: flink version 1.18.1
> iceberg version 1.15.1
> Reporter: linshangquan
> Assignee: linshangquan
> Priority: Major
> Labels: pull-request-available
> Attachments: image-2024-05-09-14-06-58-007.png,
> image-2024-05-09-14-09-38-453.png, image-2024-05-09-14-11-38-476.png,
> image-2024-05-09-14-22-14-417.png, image-2024-05-09-14-22-59-370.png,
> image-2024-05-09-18-52-03-741.png, image-2024-05-09-18-52-28-584.png
>
>
> In our scenario, we have an Iceberg table that contains a column named 'time'
> of the {{timestamptz}} data type. This column has 10 rows of data where the
> 'time' value is {{'2024-04-30 07:00:00'}} expressed in the "Asia/Shanghai"
> timezone.
> !image-2024-05-09-14-06-58-007.png!
>
> We encountered a strange phenomenon when accessing the table using
> Iceberg-flink.
> When the {{WHERE}} clause includes the {{time}} column, the results are
> incorrect.
> ZoneId.{_}systemDefault{_}() = "Asia/Shanghai"
> !image-2024-05-09-18-52-03-741.png!
> When there is no {{WHERE}} clause, the results are correct.
> !image-2024-05-09-18-52-28-584.png!
> During debugging, we found that when a {{WHERE}} clause is present, a
> {{FilterPushDownSpec}} is generated, and this {{FilterPushDownSpec}} utilizes
> {{RexNodeToExpressionConverter}} for translation.
> !image-2024-05-09-14-11-38-476.png!
> !image-2024-05-09-14-22-59-370.png!
> When {{RexNodeToExpressionConverter#visitLiteral}} encounters a
> {{TIMESTAMP_WITH_LOCAL_TIME_ZONE}} type, it uses the specified timezone
> "Asia/Shanghai" to convert the {{TimestampString}} type to an {{Instant}}
> type. However, the upstream {{TimestampString}} data has already been
> processed in UTC timezone. By applying the local timezone processing here, an
> error occurs due to the mismatch in timezones.
> Whether the handling of {{TIMESTAMP_WITH_LOCAL_TIME_ZONE}} type of data in
> {{RexNodeToExpressionConverter#visitLiteral}} is a bug, and whether it should
> process the data in UTC timezone.
>
> Please help confirm if this is the issue, and if so, we can submit a patch to
> fix it.
>
>
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