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PartitionWindowedStream does not support customizing parallelism. Its parallelism is consistent with the previous operator.

PartitionWindowedStream class will be annotated by @PublicEnvolving as more APIs may be added in the future.

Here is the fullWindowPartition method and PartitionWindowedStream class.

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Compatibility, Deprecation, and Migration Plan

This FLIP proposes a new feature in Flink. It is fully backward compatible1. PartitionWindowedStream will be annotated by @PublicEnvolving. It doesn't ensure compatibility between major releases and minor releases. It only ensures compatibility between patch releases.

Test Plan

We will provide unit and integration tests to validate the proposed changes.

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