Problem Description

When attempting to execute a complex SQL query from MDEV-32724, it will crash. To make it easier to diagnose and fix the issue, I have simplified the original query. The simplified query is intended to replicate the behavior that leads to the system crash, allowing us to focus on the core issue without getting lost in the complexity of the original query.

Original reproduce step:

CREATE TABLE x ( x INT ) ;

INSERT INTO x ( x ) VALUES ( 1 ) ;

UPDATE x SET x = 1 WHERE x = 1 ;

INSERT INTO x ( x ) VALUES ( 1 ) , ( 1 ) ;

WITH RECURSIVE x ( x ) AS ( WITH x ( x ) AS ( SELECT 1 EXCEPT SELECT x ^ 1 FROM x ) SELECT 1 FROM x AS x EXCEPT SELECT x + 1 FROM x ) SELECT - x , x FROM x ;

Minimal reproduce step:

CREATE TABLE x ( x INT ) ;

WITH RECURSIVE x ( x ) AS (

     WITH x ( x ) AS (  SELECT 1 FROM x ) 

        SELECT 1 FROM x  EXCEPT SELECT 1 FROM x )

SELECT x FROM x ;

I kindly request the development team to examine this simplified query to identify the root cause of the MDEV-32724 and fix the issue as soon as possible. By the way, please let me know if this simplified query is useful.I believe that by analyzing and fixing this simplified query, you can more easily locate the problem in the original complex query.

Thank you for your hard work and support!