ORDER BY FALSE with table operators

Detail name	Value
Changelog Number	27741
Type	Improvement
Status	Resolved
Fix Versions	Exasol 2025.2.0, Exasol 2026.1.0
Resolution Date	2025-12-17

Background

ORDER BY FALSE enforces materialization of subselects, which is a common workaround for some known bugs in Exasol (example, example, example). However, in table operators (UNION, UNION ALL, INTERSECT, EXCEPT) having ORDER BY FALSE was not allowed, even though it could also be beneficial in some scenarios.

Example

-- Observed: Error: "order by object not found"
-- Expected: Success
select x from t1
union all
select y from t2
order by false;

Improvement

ORDER BY FALSE is allowed with table operators. It does not affect query results but prevents certain optimizations.