From: | "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | oselemg(at)gmail(dot)com, pgsql-docs(at)lists(dot)postgresql(dot)org |
Subject: | Re: Typo on tutorial window page |
Date: | 2025-01-21 17:39:58 |
Message-ID: | CAKFQuwaX19XLQ79uscp9P7uyvaDhgek_tNe_bbb8p+_W5T5-dQ@mail.gmail.com |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-docs |
On Tue, Jan 21, 2025 at 10:39 AM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> PG Doc comments form <noreply(at)postgresql(dot)org> writes:
> > EXPECTED:
> > As shown here, the rank function produces a numerical rank for each
> distinct
> > PARTITION BY value in the current row's partition, using the order
> defined
> > by the ORDER BY clause. rank needs no explicit parameter, because its
> > behavior is entirely determined by the OVER clause.
>
> > ACTUAL:
> > As shown here, the rank function produces a numerical rank for each
> distinct
> > ORDER BY value in the current row's partition, using the order defined by
> > the ORDER BY clause. rank needs no explicit parameter, because its
> behavior
> > is entirely determined by the OVER clause.
>
> Hmm, I think the current text is correct, or at least more nearly
> correct than what you suggest.
> Look at the example:
>
> <programlisting>
> SELECT depname, empno, salary,
> rank() OVER (PARTITION BY depname ORDER BY salary DESC)
> FROM empsalary;
> </programlisting>
>
> <screen>
> depname | empno | salary | rank
> -----------+-------+--------+------
> develop | 8 | 6000 | 1
> develop | 10 | 5200 | 2
> develop | 11 | 5200 | 2
> develop | 9 | 4500 | 4
> develop | 7 | 4200 | 5
> personnel | 2 | 3900 | 1
> personnel | 5 | 3500 | 2
> sales | 1 | 5000 | 1
> sales | 4 | 4800 | 2
> sales | 3 | 4800 | 2
> (10 rows)
> </screen>
>
> The ranks are separate within each partition (depname), and
> within a partition rows having the same salary get the
> same rank.
>
> regards, tom lane
>
>
>
From | Date | Subject | |
---|---|---|---|
Next Message | Олег Семенов | 2025-01-21 17:44:07 | Re: Typo on tutorial window page |
Previous Message | Tom Lane | 2025-01-21 17:39:25 | Re: Typo on tutorial window page |