Adding a HASHTYPE column with default NULL to a table crashes

Detail name	Value
Changelog Number	22263
Type	Bug
Status	Resolved
Affected Versions	Exasol 8.0.0, Exasol 7.1.7
Fix Versions	Exasol 8.33.0, Exasol 8.29.6
Resolution Date	2025-01-14

Description

Adding a HASHTYPE column with an explicit default of NULL to a table causes a statement crash (“Internal server error”).

This does not depend on the size of the HASHTYPE. It does not happen for other datatypes.

Setup

create schema S;
create table A (A1 int);
insert into A values (1), (2), (3);

Example

alter table A add column A2 hashtype(16 byte) default NULL;

Workaround

Create the column without a default, and the column will be NULL by default. Or use a non-NULL value and an UPDATE.

-- Workaround 1
alter table A add column A4 hashtype(16 byte);

-- Workaround 2
alter table A add column A5 hashtype(16 byte) default '00000000000000000000000000000000';
update A set A5 = NULL;

Fix

Query runs as expected.