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https://issues.apache.org/jira/browse/HIVE-29637?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18086395#comment-18086395
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Denys Kuzmenko edited comment on HIVE-29637 at 6/5/26 2:55 PM:
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WHERE ds = `HIVE_DEFAULT_PARTITION` is a Hive-specific quirk and not something
I'd rely on semantically. __HIVE_DEFAULT_PARTITION is essentially Hive's
internal representation for partition values that are NULL.
>From a data model perspective, the partition value is still NULL, which is why
>WHERE ds IS NULL returns the same rows.
For Iceberg tables in particular, I'd strongly prefer thinking in terms of NULL
values rather than `HIVE_DEFAULT_PARTITION`. Iceberg is an interoperable table
format that can be accessed by multiple engines, and other engines are not
expected to expose or depend on Hive's internal partition naming conventions.
So I'd consider ds IS NULL the portable and semantically correct way to express
the predicate.
was (Author: dkuzmenko):
WHERE ds = '_HIVE_DEFAULT_PARTITION{_}'{_} is a Hive-specific quirk and not
something I'd rely on semantically. __HIVE_DEFAULT_PARTITION_ is essentially
Hive's internal representation for partition values that are NULL.
>From a data model perspective, the partition value is still NULL, which is why
>WHERE ds IS NULL returns the same rows.
For Iceberg tables in particular, I'd strongly prefer thinking in terms of NULL
values rather than _{_}HIVE_DEFAULT_PARTITION{_}_. Iceberg is an interoperable
table format that can be accessed by multiple engines, and other engines are
not expected to expose or depend on Hive's internal partition naming
conventions. So I'd consider ds IS NULL the portable and semantically correct
way to express the predicate.
> Iceberg: Incorrect Results for NULL Predicate on Partition Column
> -----------------------------------------------------------------
>
> Key: HIVE-29637
> URL: https://issues.apache.org/jira/browse/HIVE-29637
> Project: Hive
> Issue Type: Bug
> Reporter: Denys Kuzmenko
> Priority: Major
> Labels: pull-request-available
>
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