Setting derived column name fails for UNION ALL

Detail name	Value
Changelog Number	19318
Type	Bug
Status	Resolved
Affected Versions	Exasol 7.1.0, Exasol 8.0.0
Fix Versions	Exasol 8.29.0
Resolution Date	2024-07-12

Description

A valid query using a derived column name for a UNION ALL table fails with ‘object <column name> not found’.

Example

-- This fails with 'Error "object A1 not found"
SELECT * FROM (SELECT 1 UNION ALL SELECT 2) AS A(A1) WHERE A1 < 2;

Workaround

Give the desired column names to the columns of the first SELECT within the UNION ALL.

SELECT * FROM (SELECT 1 AS A1 UNION ALL SELECT 2) AS A(A1) WHERE A1 < 2;

Fix

Those queries run as expected.