Fix wrong results with empty grouping sets from an empty table

Detail name	Value
Changelog Number	10991
Type	Bug
Status	Resolved
Affected Versions	Exasol 7.1.0, Exasol 8.0.0
Fix Versions	Exasol 8.25.0
Resolution Date	2024-02-15

Description

The empty grouping set “()” does not produce the expected "grand total" row when selecting from an empty table.

Example

The problem only happens for an empty table:

-- Setup
create table A (A1 int);

The query should return one row but it returns no rows:

-- Expected: 1 row returned, values (0)
-- Observed: 0 rows returned
select count(*) from A group by grouping sets ((A1), ());

Workaround

There is no workaround.

Fix

The query produces the correct results.