Re: a very primitive question about division

[Martin Mueller <martinmueller@xxxxxxxxxxxxxxxx>]

In Table 9.5  the division of 9 by 4 is indeed described clearly. But there is no example of 4/9 and the different ways of formatting it as a decimal fraction with different options for rounding or a percentage.  Two or three added examples would make life easier for folks who have not progressed much beyond 8^th grade math.

 

From: "David G. Johnston" <david.g.johnston@xxxxxxxxx>
Date: Wednesday, March 7, 2018 at 11:43 AM
To: Martin Mueller <martinmueller@xxxxxxxxxxxxxxxx>
Cc: "pgsql-general@xxxxxxxxxxxxxxxxxxxx" <pgsql-general@xxxxxxxxxxxxxxxxxxxx>
Subject: Re: a very primitive question about division

 

On Wed, Mar 7, 2018 at 10:30 AM, Martin Mueller <martinmueller@xxxxxxxxxxxxxxxx> wrote:

Thanks.  So  round(before1550/colfreq::numeric, 2)  produces the desired result. 

 

The explanations and examples of string functions in the Postgres documentation are a model of clarity. The explanations and examples of basic arithmetic operations  are not.  There is room for improvement there.

 

 

Possibly.  Patches (or even just email suggestions - though the former are generally more apt to get applied) detailing specific improvements to make are welcome.

 

The description "division (integer division truncates the result)" seems reasonably clear - if you don't want the result truncated, and have two integers, you have to make one of the inputs a non-integer.  Of the various options I tend to choose numeric though others are possible.

 

David J.