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https://issues.apache.org/jira/browse/HUDI-9540?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18016530#comment-18016530
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Hans Eschbaum commented on HUDI-9540:
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!image-2025-08-27-15-25-33-375.png!
Hey [~icshuo]
I tried with:
'clean.retain_commits' = '2',
'compaction.delta_commits' = '3'
I did 5 inserts and then did incremental reads using 000 and each commit time
(including the compaction and clean commits as well) the issue seems to be the
commits between the compaction and clean, those don't show up when setting the
begin.instanttime before the compaction commit time. They show back up after
another compaction has happened.
Using the compaction commit time and later commit times show correctly.
Also `hoodie.datasource.read.incr.fallback.fulltablescan.enable=false` does
seem to have fixed the issue in my testing.
> Incremental Reads Issue With Flink
> ----------------------------------
>
> Key: HUDI-9540
> URL: https://issues.apache.org/jira/browse/HUDI-9540
> Project: Apache Hudi
> Issue Type: Bug
> Affects Versions: 1.0.2
> Reporter: Hans Eschbaum
> Priority: Major
> Attachments: image-2025-08-27-15-25-33-375.png
>
>
> Hey!
> There seems to be an issue with incremental reads with MoR tables in Flink.
>
> When I read via PySpark with, ie.
> {code:java}
> read_options = {
> 'hoodie.datasource.query.type': 'incremental',
> 'hoodie.datasource.read.begin.instanttime': '0',
> }{code}
> Some of the records do not show up that do show up with snapshot reads.
> I think this issue is likely related to the differences between MoR writes
> between Spark and Flink, where Spark always puts inserts into the base file,
> but Flink puts the inserts into the log files as well. So for some reason
> some or all of these inserts that only exist in the log files and haven't
> been compacted into base files are ignored during incremental reads.
> (My data has no deletes)
> Hudi version: 1.0.2
> Flink Version: 1.20.0
> Storage: S3
> (Writes are via AWS Managed Flink, reads are via EMR Serverless)
> To reproduce:
> 1. Do some writes via Flink to a Hudi sink
> 2. Compare an incremental read to a snapshot read, some of the records go
> missing.
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