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https://issues.apache.org/jira/browse/FLINK-21125?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17271264#comment-17271264
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Jark Wu commented on FLINK-21125:
---------------------------------
I'm fine with throwing a readable exception and suggest users to cast to
bigint. We should also take other numeric into account.
But would be better to have an option to use the max value silently. Keeping
failing and can't skip the error is dangerous for a long-running streaming job.
> Sum or Sum0 overflow quietly
> ----------------------------
>
> Key: FLINK-21125
> URL: https://issues.apache.org/jira/browse/FLINK-21125
> Project: Flink
> Issue Type: Bug
> Components: Table SQL / Planner
> Reporter: Sebastian Liu
> Priority: Major
>
> Overflow is not calculated correctly in the build-in sum function of Blink
> planner.
> For a aggregate calculation such as:
> {code:java}
> CREATE TABLE TestTable (
> amount INT
> );
> insert into TestTable (2147483647);
> insert into TestTable (1);
> SELECT sum(id) FROM TestTable;
> The result will be: -2147483648, which is an overflowed value and no
> exception was thrown. {code}
> The overflow occurs quietly and is difficult to detect.
> Compare the processing semantics of other systems：
> * *mysql*: provide two SQL mode for handling overflow. If strict SQL mode is
> enabled, MySQL rejects the out-of-range value with an error, and the insert
> fails, in accordance with the SQL standard. If no restrictive modes are
> enabled, MySQL clips the value to the appropriate endpoint of the column data
> type range and stores the resulting value instead. FYI:
> [https://dev.mysql.com/doc/refman/8.0/en/out-of-range-and-overflow.html]
> * *presto*: all numeric types are automatically auto Cast to Long type, and
> If the long is out of range, an exception is thrown to prompt user.
> IMO, exception hint is necessary, instead of quietly overflow.
>
>
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