Date: 2018-07-12 14:30:41 +0200
From: austin
To: SQL devs <>
Version: 11.29.3 (Mar2018)
CC: @njnes

Last updated: 2018-08-31 13:23:13 +0200

Comment 26547

Date: 2018-07-12 14:30:41 +0200
From: austin

Problem: Server crashes with segmentation fault when executing a query with a subselect which contains an OR-expression.

Environment:
ubuntu 16.04 in a docker container

Reproducible: Always

Steps to Reproduce:

CREATE TABLE a (a integer, b integer);
CREATE TABLE b (a integer, b integer);
SELECT (SELECT count(*) FROM b where a.a=b.a and (b.b=1 or b.b=2)) FROM a;

This is the smallest example we could find. Since even an EXPLAIN on the select does not work, it looks like the query planner already fails to parse and optimise the query. As soon as you replace the expressions of the OR-Part with something else then equals, the query will work just fine e.g.:

SELECT (SELECT count(*) FROM b where a.a=b.a and (b.b<=1 or b.b>=2)) FROM a;

Expected result:
Successful query execution without the server crashing

Comment 26551

Date: 2018-07-18 18:57:13 +0200
From: @njnes

seems to run without crashing on the March 2018 branch (after recent changes?)

Comment 26552

Date: 2018-07-18 18:58:15 +0200
From: MonetDB Mercurial Repository <>

Changeset fc8c8ae71f88 made by Niels Nes niels@cwi.nl in the MonetDB repo, refers to this bug.

For complete details, see https//devmonetdborg/hg/MonetDB?cmd=changeset;node=fc8c8ae71f88

Changeset description:

add test for bug #6625