Re: incorrect information in documentation - Mailing list pgsql-docs

From David G. Johnston
Subject Re: incorrect information in documentation
Date
Msg-id CAKFQuwbHsQ14v3i4oEwPOmgEBqEFjG4i=WsuOMmP2q82myvdQQ@mail.gmail.com
Whole thread Raw
In response to incorrect information in documentation  (PG Doc comments form <noreply@postgresql.org>)
Responses Re: incorrect information in documentation  ("David G. Johnston" <david.g.johnston@gmail.com>)
List pgsql-docs
On Mon, Aug 9, 2021 at 8:02 AM PG Doc comments form <noreply@postgresql.org> wrote:
Hello, on page
https://www.postgresql.org/docs/current/row-estimation-examples.html - there
is a example:
selectivity = (1 - null_frac1) * (1 - null_frac2) * min(1/num_distinct1,
1/num_distinct2)
            = (1 - 0) * (1 - 0) / max(10000, 10000)
            = 0.0001
in the first string  " * min" and in the second " / max"
as I understand it isn't correct.

Division is just multiplication by the reciprocal so while the presentation here is inconsistent it is correct.  Likewise, the larger a number the smaller its reciprocal, so the change from min to max also works.  

David J.

pgsql-docs by date:

Previous
From: PG Doc comments form
Date:
Subject: incorrect information in documentation
Next
From: "David G. Johnston"
Date:
Subject: Re: incorrect information in documentation