fix(core): disable ScalarSubqueryToJoin

[goldmedal]

Description

Before apache/datafusion#15334 is fixed, we need to disable ScalarSubqueryToJoin temporarily.

Summary by CodeRabbit

• Bug Fixes
  • Improved SQL query processing to avoid generating joins without conditions, ensuring valid SQL output.
• Tests
  • Enhanced test coverage to confirm correct handling of scalar subqueries and reliable query transformation.

[coderabbitai]

Walkthrough

This update removes the instantiation of the ScalarSubqueryToJoin optimizer rule in the optimize_rule_for_unparsing function to avoid generating invalid SQL join conditions. Additionally, an asynchronous test function test_disable_scalar_subquery has been added to verify that the SQL transformation correctly handles scalar subqueries. The test sets up a session context and manifest for a sample table model, analyzes a SQL query with an embedded scalar subquery, and asserts the produced SQL structure.

Changes

File	Change Summary
wren-core/.../mdl/context.rs	Removed the instantiation of ScalarSubqueryToJoin in optimize_rule_for_unparsing, commenting out the line and adding an explanatory comment.
wren-core/.../mdl/mod.rs	Added an asynchronous test function test_disable_scalar_subquery in the test module to verify proper SQL transformation for scalar subqueries.

Sequence Diagram(s)

sequenceDiagram
    participant T as Test
    participant C as Context Module
    participant O as Optimizer
    participant TS as SQL Transformer

    T->>C: Invoke test_disable_scalar_subquery()
    T->>TS: Provide SQL query and manifest
    TS->>O: Call optimize_rule_for_unparsing()
    Note over O: Rule ScalarSubqueryToJoin is excluded
    O-->>TS: Return optimized rules
    TS-->>T: Return transformed SQL
    T->>T: Assert expected SQL structure

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Suggested labels

v1-engine-changed

Suggested reviewers

• douenergy

Poem

Hoppin’ through the code with glee,
I skipped a rule, and now I’m free.
SQL joins bounce without a glitch,
Our tests confirm the code’s rich pitch.
From a rabbit’s heart so light,
Cheers to change in every byte!
🐰✨

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📥 Commits

Reviewing files that changed from the base of the PR and between a7d985c and cd4c093.

📒 Files selected for processing (2)

• wren-core/core/src/mdl/context.rs (1 hunks)
• wren-core/core/src/mdl/mod.rs (1 hunks)

🧰 Additional context used

🧬 Code Definitions (1)

wren-core/core/src/mdl/mod.rs (5)

wren-core/core/src/mdl/context.rs (1)

• new (228-231)

wren-core/core/src/logical_plan/analyze/plan.rs (6)

• new (66-78)
• new (104-117)
• new (619-621)
• new (735-829)
• new (883-930)
• new (989-991)

wren-core/core/src/logical_plan/analyze/model_anlayze.rs (3)

• new (67-75)
• new (788-796)
• analyze (45-59)

wren-core/core/src/logical_plan/analyze/model_generation.rs (2)

• new (33-38)
• analyze (232-243)

wren-core/core/src/mdl/lineage.rs (2)

• new (26-37)
• new (292-297)

⏰ Context from checks skipped due to timeout of 90000ms (6)

• GitHub Check: cargo test (win64)
• GitHub Check: cargo test (macos-aarch64)
• GitHub Check: cargo test (macos)
• GitHub Check: test
• GitHub Check: cargo check
• GitHub Check: ci

🔇 Additional comments (2)

wren-core/core/src/mdl/context.rs (1)

160-161: Temporary fix for scalar subquery optimization issue.

The ScalarSubqueryToJoin optimizer rule has been disabled to prevent generating invalid SQL with join conditions missing. This aligns with the PR objective to temporarily disable this feature until the issue is resolved in Apache DataFusion PR #15334.

wren-core/core/src/mdl/mod.rs (1)

1370-1395: Well-structured test to validate disabled optimizer rule.

This test correctly verifies that scalar subqueries remain as subqueries in the transformed SQL rather than being converted to joins, which confirms the fix in context.rs is working as intended. The test creates a simple scenario with a customer table and a query containing a scalar subquery, then validates the generated SQL structure.

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