gengliangwang opened a new pull request #29404:
URL: https://github.com/apache/spark/pull/29404
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### What changes were proposed in this pull request?
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This is a followup of https://github.com/apache/spark/pull/29125
In branch 3.0:
1. for hash aggregation, before https://github.com/apache/spark/pull/29125
there will be a runtime exception on decimal overflow of sum aggregation; after
https://github.com/apache/spark/pull/29125, there could be a wrong result.
2. for sort aggregation, with/without
https://github.com/apache/spark/pull/29125, there could be a wrong result on
decimal overflow.
While in master branch(the future 3.1 release), the problem doesn't exist
since in https://github.com/apache/spark/pull/27627 there is a flag for marking
whether overflow happens in aggregation buffer. However, the aggregation buffer
is written in steaming checkpoints. Thus, we can't change to aggregation buffer
to resolve the issue.
As there is no easy solution for returning null/throwing exception regarding
`spark.sql.ansi.enabled` on overflow in branch 3.0, we have to make a choice
here: always throw exception on decimal value overflow of sum aggregation.
### Why are the changes needed?
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Avoid returning wrong result in decimal value sum aggregation.
### Does this PR introduce _any_ user-facing change?
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Yes, there is always exception on decimal value overflow of sum aggregation,
instead of a possible wrong result.
### How was this patch tested?
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Unit test case
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