x > ALL (subquery) in the SELECT list fails with an internal schema error unless it is aliased #26622

Describe the bug

A quantified comparison such as x > ALL (SELECT ...) or x = ANY (SELECT ...) fails to plan when it appears in the SELECT list without an alias. The same query works when the expression is aliased (AS r) and when it is used in WHERE. Using it inside an aggregate, for example bool_or(x > ALL (...)), fails with Schema error: No field named "bool_or(t.x > ALL)".

The error output itself says "This issue was likely caused by a bug in DataFusion's code."

To Reproduce

CREATE TABLE t(x INT) AS VALUES (1), (6);
CREATE TABLE s(y INT) AS VALUES (5);
SELECT x > ALL (SELECT y FROM s) FROM t;
-- duckdb 1.5.6: false, true
-- datafusion main: Internal error (below)
SELECT bool_or(x > ALL (SELECT y FROM s)) FROM t;
-- duckdb 1.5.6: true
-- datafusion main: Schema error: No field named "bool_or(t.x > ALL)"

Actual output on main (datafusion-cli; schema dump shortened):

Error: Optimizer rule 'decorrelate_predicate_subquery' failed
caused by
Check optimizer-specific invariants after optimizer rule: decorrelate_predicate_subquery
caused by
Internal error: Assertion failed: compatible: Failed due to a difference in schemas: original schema: DFSchema { inner: Schema { fields: [Field { name: "t.x > ALL", data_type: Boolean, nullable: true }], ... }, new schema: DFSchema { inner: Schema { fields: [Field { name: "CASE WHEN EXISTS THEN Boolean(false) WHEN EXISTS THEN Boolean(NULL) ELSE Boolean(true) END", data_type: Boolean, nullable: true }], ... }.
This issue was likely caused by a bug in DataFusion's code. Please help us to resolve this by filing a bug report in our issue tracker: https://github.com/apache/datafusion/issues

Error: Optimizer rule 'optimize_projections' failed
caused by
Schema error: No field named "bool_or(t.x > ALL)".
Valid fields are "bool_or(CASE WHEN EXISTS THEN Boolean(false) WHEN EXISTS THEN Boolean(NULL) ELSE Boolean(true) END)".

For comparison, these work on the same build:

SELECT x > ALL (SELECT y FROM s) AS r FROM t;   -- false, true
SELECT x FROM t WHERE x > ALL (SELECT y FROM s); -- 6
SELECT x IN (SELECT y FROM s) FROM t;            -- false, false

Expected behavior

The first query should return false, true (as DuckDB 1.5.6 does), the same result as the aliased version. An optimizer rewrite should not change a plan's output schema.

Additional context

• Tested on main at c0ec512 (2026-10-22). Latest release 55.2.0 also fails: there, both queries fail in optimize_projections.
• = ANY and < ANY fail the same way.
• Cause: RewriteSetComparison::rewrite_plan (datafusion/optimizer/src/rewrite_set_comparison.rs) replaces the SetComparison with a CASE WHEN EXISTS ... expression but does not keep the original expression name. Other rewriting rules use NamePreserver for this. The output field of the Projection/Aggregate is renamed, and a later rule finds the old name missing.
• Possibly related, but not the same bug: When performing set comparison subqueries (such as > ANY / > ALL / = ANY, etc.) on the same table (without using aliases), silently returns wrong results (0 rows or all rows). #25258 and RewriteSetComparison is overly aggressive rewriting some set comparison into multiple mark joins #25276 (other set-comparison issues), Physical plan does not support logical expression Exists #23022.
• With the name preserved, the first query returns false, true. The bool_or(...) query then fails with Physical plan does not support logical expression Exists. That is a separate limitation: SELECT bool_or(exists(SELECT y FROM s)) FROM t fails the same way on main.
• Found with an automated differential/metamorphic testing tool; reproduced on current main.

Willingness to contribute

I would like to contribute a fix for this bug, but request guidance from the DataFusion community