Prepared parameters inside IN lists with tuples may cause an error

Detail name	Value
Changelog Number	29565
Type	Bug
Status	Resolved
Affected Versions	Exasol 2025.1.0, Exasol 2025.2.0
Fix Versions	Exasol 2026.1.0, Exasol 2025.1.11
Resolution Date	2026-05-15

Description

Valid queries using prepared parameters inside IN lists with tuples may lead to the incorrect error “type error: too large character string type”. This only happens if the following conditions apply:

• An IN list with tuples is inside a query.
• A tuple in the IN list contains at least one prepared parameters.
• The IN list is on an outer query.
• An inner query is materialized by the database (e.g., due to a UNION ALL or OUTER JOIN).
• The IN list is applicable on the inner query (e.g., the UNION ALL).

Example:

CREATE OR REPLACE TABLE T(x INT, y VARCHAR(100));
INSERT INTO t VALUES (1,'a'),(2,'b'),(3,'d');

-- Expected (with 'c'): 1 row
-- Observed: Error: type error: too large character string type
WITH t2 AS 
  (SELECT 'c' AS q FROM DUAL
   UNION ALL
   SELECT 'd' AS q FROM DUAL
  )
SELECT * FROM t2 WHERE (q, q) IN ((?,'c'));

Workaround

Remove the IN list:

-- Observed (with 'c'): 1 row
WITH t2 AS 
  (SELECT 'c' AS q FROM DUAL
   UNION ALL
   SELECT 'd' AS q FROM DUAL
  )
SELECT * FROM t2 WHERE q = ? and q ='c';

Fix

The queries work as intended.