Division by zero error, when should not divide at 0

[monetdb-team]

Date: 2011-09-19 18:06:59 +0200
From: Alfred Nordman <<alfred.nordman>>
To: SQL devs <>
Version: 11.3.7 (Apr2011-SP2) [obsolete]
CC: @njnes

Last updated: 2011-09-30 10:58:43 +0200

Comment 16303

Date: 2011-09-19 18:06:59 +0200
From: Alfred Nordman <<alfred.nordman>>

User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.1 (KHTML, like Gecko) Chrome/14.0.835.163 Safari/535.1
Build Identifier:

Server returns division by zero, even though it should not divide at 0.

Reproducible: Always

Steps to Reproduce:

Create table t (c int);
Insert into t values (0);
select min (case when "c" = 0 then 4 else 3/c end) from t;
drop table t;

Actual Results:

ArithmeticException:batcalc./:Division by zero

Expected Results:

a result set of one row, with the value 4

MonetDB 5 server v11.3.1 "Apr2011" (64-bit, 64-bit oids)
Copyright (c) 1993-July 2008 CWI
Copyright (c) August 2008-2011 MonetDB B.V., all rights reserved
Visit http://monetdb.cwi.nl/ for further information
Found 8.0GiB available memory
Libraries:
libpcre: 8.10 2010-06-25
openssl: OpenSSL 1.0.0a 1 Jun 2010
libxml2: 2.7.7
Compiled by: sjoerd@LAB03 (x86_64-pc-winnt)
Compilation: cl -GF -W3 -wd4273 -wd4102 -MD -nologo -Ox
Linking : cl -GF -W3 -wd4273 -wd4102 -MD -nologo -Ox

"C:\Program Files\MonetDB\MonetDB5\bin\mserver5.exe" --set "prefix=C:\Program Files\MonetDB\MonetDB5" --set "exec_prefix=C:\Program Files\MonetDB\MonetDB5" "--dbfarm=C:\Users\Rjacober\AppData\Roaming\MonetDB5\dbfarm"

Comment 16304

Date: 2011-09-19 20:11:31 +0200
From: @sjoerdmullender

Bug #2822 is very similar, but that one has been fixed.

Comment 16307

Date: 2011-09-20 10:15:10 +0200
From: @njnes

only case expressions in projections where correctly rewritten for div by zero problems. Now also group by is handled.

Comment 16308

Date: 2011-09-20 10:15:26 +0200
From: @njnes

added test div_by_zero.Bug-2887.sql

Comment 16309

Date: 2011-09-20 10:21:02 +0200
From: @njnes

Changeset 0c1fd1092f5d 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=0c1fd1092f5d

Changeset description:

fixed bug #2887, also rel_groupby is now rewritten for case/div by zero problems.

Comment 16349

Date: 2011-09-30 10:58:43 +0200
From: @grobian

Released in Aug2011-SP1