niebayes opened a new issue, #6555:
URL: https://github.com/apache/arrow-rs/issues/6555

   **Is your feature request related to a problem or challenge? Please describe 
what you are trying to do.**
   
   In our time-series database project, we always interpret timestamps without 
a timezone as being in the UTC timezone. However, when we use the [arrow 
cast](https://docs.rs/arrow/latest/arrow/compute/fn.cast.html) function to 
convert a timestamp without a timezone to a specific timezone, the result isn't 
what we expect. This is because the cast function enforces an adjustment 
internally, which causes an unintended modification to the timestamp values 
during the cast process.
   
   As specified in the 
[doc](https://docs.rs/arrow/latest/arrow/compute/fn.cast_with_options.html#casting-timestamps-without-timezone-to-timestamps-with-timezone)
 and in the comment of 
[codes](https://github.com/apache/arrow-rs/blob/9633f14f8d9e5b9b8fdf3514b7acb77217b30584/arrow-cast/src/cast/mod.rs#L1785-L1818),
  arrow cast will adjust the timestamp values if casting from a timestamp array 
without a timezone to a timestamp array with a timezone. 
   
   I propose to make such a behavior configurable and optional. 
   
   **Describe the solution you'd like**
   <!--
   A clear and concise description of what you want to happen.
   -->
   
   A sound solution may be add a boolean flag to 
[`CastOptions`](https://docs.rs/arrow/latest/arrow/compute/struct.CastOptions.html)
 to make the arrow cast function not perform such an adjustment. This boolean 
flag may be named `enable_timestamp_adjustment`.
   
   **Describe alternatives you've considered**
   <!--
   A clear and concise description of any alternative solutions or features 
you've considered.
   -->
   
   **Additional context**
   <!--
   Add any other context or screenshots about the feature request here.
   -->
   
   #5827 stated that the behavior of the arrow cast function is somewhat 
confusing.


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]

Reply via email to