[
https://issues.apache.org/jira/browse/CALCITE-6839?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17928607#comment-17928607
]
Mihai Budiu commented on CALCITE-6839:
--------------------------------------
Indeed, you can always add a cast, and that's why I think casting is a good
solution, because it lets the USER choose the type rather than the compiler.
There is however a subtle difference between adding a CAST and changing the
result type in type inference.
If you add a cast, all intermediate computations are performed starting from
this type.
For example, casting to DECIMAL may use decimal for all arithmetic, which may
be much slower than using integers.
> The SUM function sometimes throws overflow exceptions due to incorrect return
> types
> -----------------------------------------------------------------------------------
>
> Key: CALCITE-6839
> URL: https://issues.apache.org/jira/browse/CALCITE-6839
> Project: Calcite
> Issue Type: Bug
> Reporter: xiong duan
> Assignee: xiong duan
> Priority: Major
> Labels: pull-request-available
>
> The SQL in dummy.iq:
> {code:java}
> !use scott
> !set outputformat mysql
> select sum(mgr) from emp;
> !ok{code}
> Because the data type of MGR is TINYINT, according to SUM's data type
> inference rules, the data type of SUM is also TINYINT.
> This SQL throws the exception:
> {code:java}
> java.sql.SQLException: Error while executing SQL "select sum(mgr) from emp":
> Value 38835 out of range {code}
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
