HIVE-28987: Iceberg: A faulty query predicate can compromise transaction isolation

[deniskuzZ]

What changes were proposed in this pull request?

Enable conflict detection filter only when plan contains 1 TableScan Operator for a table

Why are the changes needed?

BugFix

Does this PR introduce any user-facing change?

No

How was this patch tested?

Cluster + locally
https://issues.apache.org/jira/secure/attachment/13076866/iceberg_atomic_merge_update.q

[deniskuzZ]

@simhadri-g, do you recall we have you combined using and predicates from all the TableScan operators in order to construct the final iceberg commit filter?

[deniskuzZ]

@kasakrisz, @zabetak isn't it possible to find a top level table scan operator for a specific table based on DAG plan?

[simhadri-g]

redicates from all the TableScan operators in order to construct the final iceberg commit filter?

Yes, this was the same logic spark used to build the conflict detection filter as well.
https://github.com/apache/iceberg/blob/main/spark/v3.5/spark/src/main/java/org/apache/iceberg/spark/source/SparkWrite.java#L399-L410

[deniskuzZ]

redicates from all the TableScan operators in order to construct the final iceberg commit filter?

Yes, this was the same logic spark used to build the conflict detection filter as well. https://github.com/apache/iceberg/blob/main/spark/v3.5/spark/src/main/java/org/apache/iceberg/spark/source/SparkWrite.java#L399-L410

Thanks @simhadri-g , I have no idea how Spark manages/constructs the filterExpressions, but based on the code, it seems Spark has a single TS operator (root TS ???).
Maybe you can check with @vrozov and help us do the same in Hive.

scan.filterExpressions()

In the current PR, since I don't have any better ideas how to identify root TS and construct the final filterExpressions, I am disabling the conflict detection filter when DAG has multiple TS operators for the write table.
cc @okumin

[kasakrisz]

+1 pending tests

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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