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From Michael McAllister <mmcallis...@homeaway.com>
Subject RE: can I prevent rounding of a/b when a and b are integers
Date Thu, 22 Sep 2016 15:42:34 GMT
Actually, in Oracle, at least the last time I was working on it, if you divided an int column
by an int column, you got an int result which, if I remember correctly, was truncated.

For people who write SQL, this is a fairly well known issue that we confront, and solve using
the solution proposed below. Either by multiplying one of the operands by 1.0, or casting
one of them as a real number.

Additionally, don’t lose sight of the warning James Heather raised in one of the earlier
responses. Make sure you restrict what your users do. Having a table dropped could end up
being very expensive.

Michael McAllister
Staff Data Warehouse Engineer | Decision Systems
mmcallister@HomeAway.com<mailto:mmcallister@HomeAway.com> | C: 512.423.7447 | skype:
michael.mcallister.ha<mailto:zimmkate@hotmail.com> | webex: https://h.a/mikewebex
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From: Bulvik, Noam [mailto:Noam.Bulvik@teoco.com]
Sent: Thursday, September 22, 2016 5:25 AM
To: user@phoenix.apache.org
Subject: RE: can I prevent rounding of a/b when a and b are integers

I checked both oracle and impala and in both 1/3 is 0.333 and not 0.
I think that SQL writer is not a programmer and he  does not care about data type. He just
want to get the correct results. BTW – it is not only constant, even expression like sum(case
when <condition > then 1 else 0 end) / count(*) will get wrong results unless you will
start implementing workarounds

From: John Hancock [mailto:jhancock1975@gmail.com]
Sent: Thursday, September 22, 2016 12:56 PM
To: user@phoenix.apache.org<mailto:user@phoenix.apache.org>
Subject: Re: can I prevent rounding of a/b when a and b are integers

I think it is fairly standard in programming languages for / to mean integer division when
the operands used are integers.  Therefore 1/3=0 is not a surprising result to me; other programming
languages I have worked in give 1/3=0.  However if one of the operands to / is a decimal,
the result is also decimal, so 1.0/3 = 0.333... I don't think the behavior of / is incorrect
as is.

On Thu, Sep 22, 2016 at 4:45 AM, Heather, James (ELS-LON) <james.heather@elsevier.com<mailto:james.heather@elsevier.com>>
wrote:


On Thu, 2016-09-22 at 05:39 +0000, Bulvik, Noam wrote:

We have an app that let user write their own SQL

Um, do they write DROP TABLE statements in there?

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