* fix(query): insert MergeScan into nested scalar subqueries
DataFusion 55 keeps uncorrelated scalar subqueries as expression
subqueries (enable_physical_uncorrelated_scalar_subquery, default true)
instead of decorrelating them into joins, and executes them via the new
physical ScalarSubqueryExec. DistPlannerAnalyzer::try_push_down walked
the plan with a plain TreeNode transform that does not descend into
expression subqueries, so MergeScan was only inserted for depth-1
subqueries. A scalar subquery nested inside another scalar subquery kept
a bare frontend DistTable TableScan and failed at execution with
"Unsupported operation: get stream from a distributed table".
Use the subquery-aware transform so handle_subquery (PlanRewriter /
MergeScan insertion) runs for subquery plans at every nesting depth.
Fixes#9260.
Signed-off-by: discord9 <55937128+discord9@users.noreply.github.com>
* test(query): strengthen nested scalar subquery regression coverage
Address review on #9261:
- Replace the ineffective 'no bare TableScan' string check with a real
subquery-aware plan walk (apply_with_subqueries); MergeScan hides its
remote input from traversal, so any TableScan the walk reaches was
genuinely left unwrapped.
- Add a distributed regression case on a range-partitioned table so the
nested inner aggregate must merge partial results across regions
(global AVG feeding an outer SUM filter).
Signed-off-by: discord9 <55937128+discord9@users.noreply.github.com>
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Signed-off-by: discord9 <55937128+discord9@users.noreply.github.com>
Add ORDER BY clause to subquery union tests
Updated the SQL and result files for subquery union tests to include an ORDER BY clause, ensuring consistent result ordering. This change aligns with the test case from the DuckDB repository.
discord9
Lei, HUANG
Yohan Wal