New filter elimination may cause internal server error

Detail name	Value
Changelog Number	6582
Type	Bug
Status	Resolved
Affected Versions	Exasol 6.1.rc1
Fix Versions	Exasol 6.1.0
Resolution Date	2018-09-04

Background

Exasol 6.1 (beta 1) introduces improved filter propagation and elimination, which should lead to better overall performance.

Problem Description

If there are two equivalent filters where left and right operands are swapped, filter elimination doesn't work correctly and may cause internal server error.

Example:

create table t_1 (c_id DECIMAL(20,0));

select
	*
from
	t_1 as a,
	t_1 as b,
	t_1 as c
WHERE
	a.c_id = b.c_id   -- here
AND
	a.c_id = c.c_id
AND
	b.c_id = c.c_id
AND
	b.c_id = a.c_id  -- and here
;

Response:

[40005] Successfully reconnected after internal server error, transaction was rolled back.