[
https://issues.apache.org/jira/browse/BEAM-1956?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17546517#comment-17546517
]
Kenneth Knowles commented on BEAM-1956:
---------------------------------------
This issue has been migrated to https://github.com/apache/beam/issues/18379
> Flatten operation should respect input type hints.
> --------------------------------------------------
>
> Key: BEAM-1956
> URL: https://issues.apache.org/jira/browse/BEAM-1956
> Project: Beam
> Issue Type: Bug
> Components: sdk-py-core
> Reporter: Vikas Kedigehalli
> Priority: P3
>
> Input type hints are currently not respected by the Flatten operation and
> instead `Any` type is chosen as a fallback. This could lead to using a pickle
> coder even if there was a custom coder type hint provided for input
> PCollections.
> Also, this could lead to undesirable results, particularly, when a Flatten
> operation is followed by a GroupByKey operation which requires the key coder
> to be deterministic. Even if the user provides deterministic coder type hints
> to their PCollections, defaulting to Any would result in using the pickle
> coder (non-deterministic). As a result of this, CoGroupByKey is broken in
> such scenarios where input PCollection coder is deterministic for the type
> while pickle coder is not.
--
This message was sent by Atlassian Jira
(v8.20.7#820007)
