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https://issues.apache.org/jira/browse/ARROW-14122?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17420386#comment-17420386
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Phillip Cloud commented on ARROW-14122:
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[~jorgecarleitao] If I understand correctly the antisymmetry relation doesn't
hold for compound interval values with components that mix {{>= day}} and {{<
day}} resolution because {{<=}} and {{>=}} operations are not well defined for
those types, so the evaluating the statement "is a <= b and b <= a?" cannot be
done without knowledge of the reference point. For example:
{code:sql}
interval '1 day -1 millisecond'
interval '86399999 milliseconds'
{code}
These two values cannot be distinctly ordered without additional information.
For example, DST might cause a day's length to be something other than 24
hours, which would make these two values compare less than, equal to, and
greater than, depending on what the start and end points of the interval are.
I don't think Arrow intervals except for Month, have a well-defined partial or
total ordering, nor can they be compared for equality.
I don't think we should special case anything here either. Partial
functionality like "only month intervals can be compared" or "month intervals
and intervals whose values don't mix >= day and < day resolution units can be
compared". I think this will generate a lot of confusion about what operations
are valid on what values.
[~houqp] I brought up that PR as a point of reference for my claim that I don't
think there's any interval comparison implementation whose functionality cannot
be achieved with comparing the output from a set of time-units-between
functions. That includes hashing needed for grouped aggregations, as well as
comparison for sorting.
I am -1 on implementing any kind of comparison operations for Arrow interval
types.
> [C++] interval comparison kernels
> ---------------------------------
>
> Key: ARROW-14122
> URL: https://issues.apache.org/jira/browse/ARROW-14122
> Project: Apache Arrow
> Issue Type: Sub-task
> Reporter: Phillip Cloud
> Priority: Major
> Labels: kernel
>
> Subtask for tracking interval comparison kernels
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