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https://issues.apache.org/jira/browse/FLINK-21125?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17272689#comment-17272689
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Sebastian Liu commented on FLINK-21125:
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Hi [~jark],
Thx for your comprehensive analysis. I also think that we should still keep the
original behavior which is similar to Spark Sql or Hive. This relatively keep
rigorous and flexible.
The config of table.exec.numeric-overflow.handling is more reasonable. I
suggest we use the following item:
* *{{unchecked -> ignore}}*
* *error*
* *silent -> warn*
what do you think of this?
> 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(amount) 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 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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