Order of evaluation of the modulo operator

[monetdb-team]

Date: 2017-02-22 09:52:32 +0100
From: Frédéric Jolliton <<frederic.jolliton+monetdb>>
To: SQL devs <>
Version: 11.25.5 (Dec2016-SP1)

Last updated: 2017-07-17 16:07:33 +0200

Comment 25053

Date: 2017-02-22 09:52:32 +0100
From: Frédéric Jolliton <<frederic.jolliton+monetdb>>

User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.75 Safari/537.36
Build Identifier:

The modulo operator should have the same order of evaluation as the division.

• 1010/3 == 33, since it is evaluated as (1010)/3.
• 1010%3 == 10, which is wrong because it was evaluated as 10(10%3)

Reproducible: Always

Steps to Reproduce:

Evaluate 10 * 10 % 3

Actual Results:

10

Expected Results:

1

Comment 25084

Date: 2017-03-02 17:48:39 +0100
From: MonetDB Mercurial Repository <>

Changeset 469a57574048 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=469a57574048

Changeset description:

Fixed operator precedence of % to be equal to * and /.
This fixes bug #6225.

Comment 25085

Date: 2017-03-02 17:51:31 +0100
From: @sjoerdmullender

The SQL standard doesn't mention the % operator for modulo/remainder, so I guess we can do whatever we want. But I agree it's a good idea to follow the lead of languages such as C where % / and * all have equal priority.

The SQL standard only mentions MOD as in
::=
<MOD