Date: 2019-08-19 17:03:50 +0200
From: @PedroTadim
To: SQL devs <>
Version: 11.33.3 (Apr2019)

Last updated: 2020-06-03 16:58:53 +0200

Comment 27237

Date: 2019-08-19 17:03:50 +0200
From: @PedroTadim

User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.100 Safari/537.36
Build Identifier:

Do the reproducible steps.

Reproducible: Always

Steps to Reproduce:

1. create table tab1 (col1 clob);
2. create remote table tab1 (col1 clob, col2 int) on 'mapi:monetdb://'; --on another server
3. select col2 from tab1; --this crashes the remote server.

Actual Results:

SIGSEV on exps_mark_used

Expected Results:

An error should be thrown saying the column doesn't exist.

Thread 24 "mserver5" received signal SIGSEGV, Segmentation fault.

exps_mark_used (sa=0x7fffc4001800, rel=0x7fffc40f4230, subrel=0x7fffc40f3f00) at ../../../src/sql/server/rel_optimizer.c:6079
6079 exps[0]->used = 1;
Missing separate debuginfos, use: dnf debuginfo-install libpq-11.5-1.fc30.x86_64
(gdb) bt
0 exps_mark_used (sa=0x7fffc4001800, rel=0x7fffc40f4230, subrel=0x7fffc40f3f00) at ../../../src/sql/server/rel_optimizer.c:6079
1 0x00007fffe87b382d in rel_mark_used (sql=0x7fffc40111f0, rel=0x7fffc40f4230, proj=1) at ../../../src/sql/server/rel_optimizer.c:6187
2 0x00007fffe87b49f5 in rel_dce_sub (sql=0x7fffc40111f0, rel=0x7fffc40f4230) at ../../../src/sql/server/rel_optimizer.c:6677
3 0x00007fffe87b4e06 in rel_dce (sql=0x7fffc40111f0, rel=0x7fffc40f4230) at ../../../src/sql/server/rel_optimizer.c:6771
4 0x00007fffe87c1b57 in optimize_rel (sql=0x7fffc40111f0, rel=0x7fffc40f4230, g_changes=0x7fffd4893120, level=0, value_based_opt=0) at ../../../src/sql/server/rel_optimizer.c:9703
5 0x00007fffe87c1e01 in optimize (sql=0x7fffc40111f0, rel=0x7fffc40f4230, value_based_opt=0) at ../../../src/sql/server/rel_optimizer.c:9779
6 0x00007fffe87c1f10 in rel_optimizer (sql=0x7fffc40111f0, rel=0x7fffc40f4230, value_based_opt=0) at ../../../src/sql/server/rel_optimizer.c:9795
7 0x00007fffe869b018 in RAstatement2 (cntxt=0x7fffe91086e0, mb=0x7fffc4005d30, stk=0x7fffc400a850, pci=0x7fffc40ee710) at ../../../../src/sql/backends/monet5/sql_execute.c:1004
8 0x00007ffff7dc30e8 in runMALsequence (cntxt=0x7fffe91086e0, mb=0x7fffc4005d30, startpc=1, stoppc=0, stk=0x7fffc400a850, env=0x7fffc400a850, pcicaller=0x0) at ../../../src/monetdb5/mal/mal_interpreter.c:647
9 0x00007ffff7dc1774 in runMAL (cntxt=0x7fffe91086e0, mb=0x7fffc4005d30, mbcaller=0x0, env=0x7fffc400a850) at ../../../src/monetdb5/mal/mal_interpreter.c:336
10 0x00007ffff7df2d1c in MALengine (c=0x7fffe91086e0) at ../../../src/monetdb5/mal/mal_session.c:752
11 0x00007ffff7def9db in runPhase (c=0x7fffe91086e0, phase=4) at ../../../src/monetdb5/mal/mal_scenario.c:517
12 0x00007ffff7defb77 in runScenarioBody (c=0x7fffe91086e0, once=0) at ../../../src/monetdb5/mal/mal_scenario.c:547
13 0x00007ffff7defda8 in runScenario (c=0x7fffe91086e0, once=0) at ../../../src/monetdb5/mal/mal_scenario.c:580
14 0x00007ffff7df1ba9 in MSserveClient (c=0x7fffe91086e0) at ../../../src/monetdb5/mal/mal_session.c:525
15 0x00007ffff7df1671 in MSscheduleClient (command=0x7fffc4003610 '\275' <repeats 200 times>..., challenge=0x7fffd4895cbb "e8JertRm", fin=0x7fffc4007580, fout=0x7fffd0007180, protocol=PROTOCOL_9, blocksize=8190) at ../../../src/monetdb5/mal/mal_session.c:403
16 0x00007ffff7e9f511 in doChallenge (data=0x7fffd0004f10) at ../../../../src/monetdb5/modules/mal/mal_mapi.c:271
17 0x00007ffff7b33cc8 in THRstarter (a=0x7fffd0009270) at ../../src/gdk/gdk_utils.c:1415
18 0x00007ffff7badda2 in thread_starter (arg=0x7fffbc0039e0) at ../../src/gdk/gdk_system.c:650
19 0x00007ffff6d685a2 in start_thread (arg=) at pthread_create.c:486
20 0x00007ffff6c95303 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Comment 27238

Date: 2019-08-19 17:10:59 +0200
From: MonetDB Mercurial Repository <>

Changeset 1d9ee75506c2 made by Pedro Ferreira pedro.ferreira@monetdbsolutions.com in the MonetDB repo, refers to this bug.

For complete details, see https//devmonetdborg/hg/MonetDB?cmd=changeset;node=1d9ee75506c2

Changeset description:

Added test for bug #6750.

Comment 27253

Date: 2019-08-23 11:04:49 +0200
From: MonetDB Mercurial Repository <>

Changeset 83441f76c441 made by Pedro Ferreira pedro.ferreira@monetdbsolutions.com in the MonetDB repo, refers to this bug.

For complete details, see https//devmonetdborg/hg/MonetDB?cmd=changeset;node=83441f76c441

Changeset description:

Updated bug #6750 test with another issue: remote tables referencing merge tables in a loop

Comment 27579

Date: 2020-02-24 15:55:25 +0100
From: MonetDB Mercurial Repository <>

Changeset 39e8f7c93323 made by Pedro Ferreira pedro.ferreira@monetdbsolutions.com in the MonetDB repo, refers to this bug.

For complete details, see https//devmonetdborg/hg/MonetDB?cmd=changeset;node=39e8f7c93323

Changeset description:

Progress for bug #6750 resolution, ie whenever an error is found at rel_read, set it and throw it

Comment 27580

Date: 2020-02-25 10:55:06 +0100
From: MonetDB Mercurial Repository <>

Changeset b0dc972ef4c0 made by Pedro Ferreira pedro.ferreira@monetdbsolutions.com in the MonetDB repo, refers to this bug.

For complete details, see https//devmonetdborg/hg/MonetDB?cmd=changeset;node=b0dc972ef4c0

Changeset description:

Final fix for bug #6750, ie send an extra string with the expected output types for the sending relation and verify it at the other side