[BugFix] fix the column not found issue in skew join hint

[murphyatwork]

Why I'm doing:

What I'm doing:

Skew join hint should be able to support both left side and right side.

Fixes #66924

What type of PR is this:

• BugFix
• Feature
• Enhancement
• Refactor
• UT
• Doc
• Tool

Does this PR entail a change in behavior?

• Yes, this PR will result in a change in behavior.
• No, this PR will not result in a change in behavior.

If yes, please specify the type of change:

• Interface/UI changes: syntax, type conversion, expression evaluation, display information
• Parameter changes: default values, similar parameters but with different default values
• Policy changes: use new policy to replace old one, functionality automatically enabled
• Feature removed
• Miscellaneous: upgrade & downgrade compatibility, etc.

Checklist:

• I have added test cases for my bug fix or my new feature
• This pr needs user documentation (for new or modified features or behaviors)
  • I have added documentation for my new feature or new function
• This is a backport pr

Bugfix cherry-pick branch check:

• I have checked the version labels which the pr will be auto-backported to the target branch
  • 4.0
  • 3.5
  • 3.4
  • 3.3

---

Note

Enables skew join hints to reference columns from either the left or right join side by fixing scope analysis and optimizer transformations, with new tests verifying right-side hints.

• Analyzer:
  • analyzeJoinHints now receives leftScope/rightScope; skew column is analyzed against a combined join scope.
• Optimizer (SkewJoinOptimizeRule):
  • Properly finds the counterpart column for the skew key regardless of which side it’s on.
  • Renames/rewires helpers (addSaltForSkewChild/addSaltForOtherChild) and applies salt to the correct child based on column lineage.
  • Tightens validation when hint is used but skew column counterpart isn’t found.
• Transformer:
  • Translates join[skew|...] column using a builder that includes both left/right plans, enabling right-side column support.
• Tests:
  • Add cases validating right-side skew hints in both v1 and v2 planner modes.

^{Written by Cursor Bugbot for commit 1bcfe9f. This will update automatically on new commits. Configure here.}

[Copilot]

Pull request overview

This PR fixes a bug where skew join hints would fail with a "column not found" error when referencing columns from the right side of a join. Previously, the skew join optimization only resolved columns against the left relation's scope, preventing users from specifying skew columns on the right table (e.g., join[skew|t1.v4(1,2)]). The fix enables bidirectional support by resolving skew columns against a combined scope of both join relations and dynamically determining which side contains the skew column during optimization.

Key changes:

• Column resolution now checks both left and right relations to find the skew column
• Optimization logic determines skew column side dynamically and applies salt operations accordingly
• Variable renaming from side-specific (rightSkewColumn) to side-agnostic (otherSideSkewColumn) names

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
fe/fe-core/src/main/java/com/starrocks/sql/analyzer/QueryAnalyzer.java	Modified analyzeJoinHints to accept both left and right scopes, creating a joined scope for skew column resolution
fe/fe-core/src/main/java/com/starrocks/sql/optimizer/transformer/RelationTransformer.java	Updated skew column translation to pass both left and right OptExprBuilders for bidirectional column lookup
fe/fe-core/src/main/java/com/starrocks/sql/optimizer/rule/transformation/SkewJoinOptimizeRule.java	Enhanced optimization rule to detect which side contains the skew column and renamed methods/variables to be side-agnostic
fe/fe-core/src/test/java/com/starrocks/sql/plan/SkewJoinV2Test.java	Added test case verifying right-side skew column hints work correctly with V2 optimization
fe/fe-core/src/test/java/com/starrocks/sql/plan/SkewJoinTest.java	Added test case verifying right-side skew column hints work correctly with standard optimization

[sonarqubecloud]

Quality Gate passed

Issues
11 New issues
0 Accepted issues

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

See analysis details on SonarQube Cloud

[alvin-celerdata]

@cursor review

[cursor]

✅ Bugbot reviewed your changes and found no bugs!

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[github-actions]

[Java-Extensions Incremental Coverage Report]

✅ pass : 0 / 0 (0%)

[github-actions]

[FE Incremental Coverage Report]

✅ pass : 37 / 37 (100.00%)

file detail

	path	covered_line	new_line	coverage	not_covered_line_detail
🔵	com/starrocks/sql/optimizer/transformer/RelationTransformer.java	1	1	100.00%	[]
🔵	com/starrocks/sql/optimizer/rule/transformation/SkewJoinOptimizeRule.java	32	32	100.00%	[]
🔵	com/starrocks/sql/analyzer/QueryAnalyzer.java	4	4	100.00%	[]

[github-actions]

[BE Incremental Coverage Report]

✅ pass : 0 / 0 (0%)