Internal server error for duplicate GROUP_CONCAT/LISTAGG analytic functions

Detail name	Value
Changelog Number	11045
Type	Bug
Status	Resolved
Affected Versions	Exasol 6.2.0, Exasol 7.0.0
Fix Versions	Exasol 7.0.4
Resolution Date	2020-11-26

Description

A query may return an internal server error, if the following conditions are met:

• The query contains either GROUP_CONCAT or LISTAGG without ON OVERFLOW TRUNCATE as analytic functions.
• One of the functions is used multiple times with equivalent parameters in the SELECT list.

Examples

SELECT GROUP_CONCAT(a) OVER(), GROUP_CONCAT(a) OVER() FROM t;
SELECT LISTAGG(a) OVER() = LISTAGG(a) OVER() FROM t;
SELECT LISTAGG(a) OVER() AS x, local.x FROM t;

Workaround

Slightly modify the second function call:

SELECT LISTAGG(a) OVER(), LISTAGG(a || '') OVER() FROM t;

Fix

Multiple equivalent function calls for GROUP_CONCAT/LISTAGG as analytic functions are supported.