Re: a very primitive question about division

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 8th grade math.

From: "David G. Johnston" <david.g.johnston@gmail.com>
Date: Wednesday, March 7, 2018 at 11:43 AM
To: Martin Mueller <martinmueller@northwestern.edu>
Cc: "pgsql-general@lists.postgresql.org" <pgsql-general@lists.postgresql.org>
Subject: Re: a very primitive question about division

On Wed, Mar 7, 2018 at 10:30 AM, Martin Mueller <martinmueller@northwestern.edu<mailto:martinmueller@northwestern.edu>> 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.