Assertion hit in the codegen

[monetdb-team]

Date: 2016-11-09 11:05:15 +0100
From: Dean De Leo <>
To: SQL devs <>
Version: -- development
CC: @njnes

Last updated: 2016-12-21 13:07:46 +0100

Comment 24658

Date: 2016-11-09 11:05:15 +0100
From: Dean De Leo <>

User-Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.71 Safari/537.36
Build Identifier:

Hello, I'm hitting the attached assertion somewhere in the codegen.

On Linux, tip of the default branch, debug build, empty tables.

Reproducible: Always

Steps to Reproduce:

1. Start a fresh of mserver5
2. Issue the attached query. The schema is included.
3. Boom

Actual Results:

See attached back trace.

Expected Results:

Server failures are bad. Assuming they should never occur.

Comment 24659

Date: 2016-11-09 11:05:56 +0100
From: Dean De Leo <>

Created attachment 495
Repro query, schema included

Attached file: query2_crash_repro.sql (application/sql, 1396 bytes)
Description: Repro query, schema included

Comment 24660

Date: 2016-11-09 11:06:44 +0100
From: Dean De Leo <>

Created attachment 496
Backtrace

Attached file: backtrace2.txt (text/plain, 7597 bytes)
Description: Backtrace

Comment 24671

Date: 2016-11-09 23:07:09 +0100
From: MonetDB Mercurial Repository <>

Changeset bfc05edc1fa1 made by Niels Nes niels@cwi.nl in the MonetDB repo, refers to this bug.

For complete details, see http//devmonetdborg/hg/MonetDB?cmd=changeset;node=bfc05edc1fa1

Changeset description:

fixes for bugs 6114, 6115, 6116 and 6117

improved dead code elimination for cases with references to sub queries (ie its a dag)
push simple select like expressions downs

split_project test is added here but only crashes in the dec2016/default.

Comment 24675

Date: 2016-11-10 08:05:29 +0100
From: @njnes

fixed by the some solution as bug #6114 (ie dead code elimination)