Fixed a crash when formatting zero DOUBLE values using scientific notation.

Detail name	Value
Changelog Number	30856
Type	Bug
Status	Resolved
Affected Versions	Exasol 7.1.0, Exasol 8.0.0, Exasol 8.29.0, Exasol 2025.1.0, Exasol 2026.1.0
Fix Versions	Exasol 2026.1.1, Exasol 2025.1.13
Resolution Date	2026-07-15

Description

A query that formats a DOUBLE value using TO_CHAR with a scientific notation format model may cause an internal server error or return wrong results.

This happens if all the following criteria are met and appear in the same query:

• The query contains TO_CHAR.
• The input value is of type DOUBLE.
• The format model uses scientific notation, for example '9EEEE'.
• The input value is 0.

Example

-- Expected: 1 row, values e.g. ("0E+00")
-- Observed: Internal server error
SELECT TO_CHAR(CAST(0 AS DOUBLE), '9EEEE');

CREATE TABLE A (A1 DOUBLE);
INSERT INTO A VALUES (0);

-- Expected: 1 row, values e.g. ("0E+00")
-- Observed: Internal server error
SELECT TO_CHAR(A1, '9EEEE') FROM A;

Workaround

Cast the DOUBLE value to an appropriate DECIMAL type before calling TO_CHAR, for example DECIMAL(36,18).

SELECT TO_CHAR(CAST(CAST(0 AS DOUBLE) AS DECIMAL(36,18)), '9EEEE');

CREATE TABLE A (A1 DOUBLE);
INSERT INTO A VALUES (0);

SELECT TO_CHAR(CAST(A1 AS DECIMAL(36,18)), '9EEEE') FROM A;

Fix

TO_CHAR now correctly formats DOUBLE zero values when scientific notation is requested. Queries return the expected formatted result instead of failing or producing incorrect output.