Hive 29574 merge join poc

[illiabarbashov-sketch]

What changes were proposed in this pull request?

1. New Hive configurations: hive.merge.join.skew.threshold and hive.merge.join.skew.abort
2. A new SkewedMergeJoinMonitor class to manage those configurations and log skew join event or abort it.
3. Unit tests to cover positive and negative cases
4. Query tests to cover clientpositive and clientnegative test cases

Why are the changes needed?

1. This feature adds observability to merge join operator and flags the skewed keys
2. Clients have problem with Skewed Merge Join when the job is stuck and there are no progress and no information about the reasons behind this issue. This feature adds a configuration to abort the stuck job if the threshold is hit.

Does this PR introduce any user-facing change?

No

How was this patch tested?

• Unit tests
• Query tests with clientpositive and clientnegative cases

[sonarqubecloud]

Quality Gate passed

Issues
41 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.3% Duplication on New Code

See analysis details on SonarQube Cloud