median function with "group by" - SIGSEGV

[monetdb-team]

Date: 2013-10-22 18:19:10 +0200
From: Klaudiusz <>
To: SQL devs <>
Version: 11.15.17 (Feb2013-SP5)

Last updated: 2013-12-03 13:59:40 +0100

Comment 19297

Date: 2013-10-22 18:19:10 +0200
From: Klaudiusz <>

User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.101 Safari/537.36
Build Identifier:

median of set with one value (?) with "group by" doesn't work.

Reproducible: Always

Steps to Reproduce:

CREATE table a (k int,b int);
INSERT into a values (1,2);
INSERT into a values (2,2);
INSERT into a values (3,3);
INSERT into a values (4,65);
INSERT into a values (5,21);
INSERT into a values (6,null);
INSERT into a values (7,null);
INSERT into a values (8,null);
INSERT into a values (9,null);

SELECT median(b) from a group by k;

Actual Results:

mclient exited.
In merovingian.log:
MSG merovingian[5991]: database 'test' (6210) was killed by signal SIGSEGV

Expected Results:

+--------------------------+
| L1 |
+==========================+
| 2 |
| 2 |
| 3 |
| 65 |
| 21 |
| null |
| null |
| null |
| null |
+--------------------------+

MonetDB 5 server v11.15.18 (64-bit, 64-bit oids)
This is an unreleased version
Copyright (c) 1993-July 2008 CWI
Copyright (c) August 2008-2013 MonetDB B.V., all rights reserved
Visit http://www.monetdb.org/ for further information
Found 252.2GiB available memory, 32 available cpu cores
Libraries:
libpcre: 7.8 2008-09-05 (compiled with 7.8)
openssl: OpenSSL 1.0.0 29 Mar 2010 (compiled with OpenSSL 1.0.0-fips 29 Mar 2010)
libxml2: 2.7.6 (compiled with 2.7.6)
Compiled by: (x86_64-unknown-linux-gnu)
Compilation: gcc -g -Werror -Wall -Wextra -W -Werror-implicit-function-declaration -Wpointer-arith -Wdeclaration-after-statement -Wformat=2 -Wno-format-nonliteral -Winit-self -Winvalid-pch -Wmissing-declarations -Wmissing-format-attribute -Wmissing-prototypes -Wold-style-definition -Wpacked -Wunknown-pragmas -Wvariadic-macros -fstack-protector-all -Wstack-protector -Wpacked-bitfield-compat -Wsync-nand -Wmissing-include-dirs
Linking : /usr/bin/ld -m elf_x86_64

Comment 19298

Date: 2013-10-22 20:43:10 +0200
From: MonetDB Mercurial Repository <>

Changeset fb66b11cc3bd made by Sjoerd Mullender sjoerd@acm.org in the MonetDB repo, refers to this bug.

For complete details, see http//devmonetdborg/hg/MonetDB?cmd=changeset;node=fb66b11cc3bd

Changeset description:

When calculating grouped medians, deal with dense group bat.
Also added test.
This fixes bug #3389.

Comment 19299

Date: 2013-10-22 20:45:29 +0200
From: @sjoerdmullender

Fixed.

Comment 19388

Date: 2013-12-03 13:59:40 +0100
From: @sjoerdmullender

Feb2013-SP6 has been released.