[
https://issues.apache.org/jira/browse/HIVE-5436?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13809704#comment-13809704
]
Xuefu Zhang commented on HIVE-5436:
-----------------------------------
[~hsubramaniyan] thanks for your explanation. Personally I think for HIVE-5382,
current focus might be on making iin-range casting work as expected and letting
error handling cases be unified until HIVE-5660. Per interdeciate result, Hive
evaluates on an expression tree. In general, the moment a node evaluates to
null, the parent operator evaluates to null also.
Feel free to work on HIVE-5660 if you like. I'm just a little bit concerned
that the work you done will probably be thrown away because of HIVE-5356. This
is why I planned to work on it after HIVE-5356, which I'm current working on.
Pleases. let me know your plan. Thank
> Hive's casting behavior needs to be consistent
> ----------------------------------------------
>
> Key: HIVE-5436
> URL: https://issues.apache.org/jira/browse/HIVE-5436
> Project: Hive
> Issue Type: Bug
> Reporter: Hari Sankar Sivarama Subramaniyan
> Assignee: Hari Sankar Sivarama Subramaniyan
> Priority: Critical
>
> Hive's casting behavior is inconsistent and the behavior of casting from one
> type to another undocumented as of now when the casted value is out of range.
> For example, casting out of range values from one type to another can result
> in incorrect results.
> Eg:
> 1. select cast('1000' as tinyint) from t1;
> NULL
> 2. select 1000Y from t1;
> FAILED: SemanticException [Error 10029]: Line 1:7 Invalid numerical constant
> '1000Y'
> 3. select cast(1000 as tinyint) from t1;
> -24
> 4.select cast(1.1e3-1000/0 as tinyint) from t1;
> 0
> 5. select cast(10/0 as tinyint) from pw18;
> -1
> The hive user can accidently try to typecast an out of range value. For
> example in the e.g. 4/5 even though the final result is NaN, Hive can
> typecast to a random result. Either we should document that the end user
> should take care of overflow, underflow, division by 0, etc. by
> himself/herself or we should return NULLs when the final result is out of
> range.
--
This message was sent by Atlassian JIRA
(v6.1#6144)
