Date: 2018-01-31 00:15:17 +0100
From: Trevor <>
To: SQL devs <>
Version: 11.27.11 (Jul2017-SP3)
CC: @njnes

Last updated: 2018-02-12 16:12:09 +0100

Comment 26138

Date: 2018-01-31 00:15:17 +0100
From: Trevor <>

User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:58.0) Gecko/20100101 Firefox/58.0
Build Identifier:

A crash occurs when using an alias to a column in a subquery.

See the example below:

create table "t1" ("d1" int);
insert into "t1" values (1), (2), (3), (4), (5);

-- Works
select
"d1" as "value"
from "t1"
order by "value";

-- Works
select
a."value"
from (
select
"d1" as "value"
from "t1"
order by "d1"
) as a;

-- Crashes
select
a."value"
from (
select
"d1" as "value"
from "t1"
order by "value"
) as a;

From merovingian.log:
2018-01-30 17:10:15 ERR test[26999]: could not find L2.value
2018-01-30 17:10:15 ERR test[26999]: t1.d1
2018-01-30 17:10:15 ERR test[26999]: a.value
2018-01-30 17:10:15 ERR test[26999]: *** Error in `/usr/bin/mserver5': double free or corruption (out): 0x00007f95980cb810 ***

Reproducible: Always

Steps to Reproduce:

Run the queries in the details.

Actual Results:

Database crashes.

Expected Results:

Query should complete.

Comment 26151

Date: 2018-01-31 18:53:29 +0100
From: @njnes

fixed problem with table aliases

Comment 26152

Date: 2018-01-31 21:53:32 +0100
From: MonetDB Mercurial Repository <>

Changeset f0b5bb2c3ac9 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=f0b5bb2c3ac9

Changeset description:

fixed bug #6527 (be more carefull with order by and table aliases)