agora inbox for pgsql-docs@postgresql.org
help / color / mirror / Atom feedFrom: Tom Lane <tgl@sss.pgh.pa.us>
To: oselemg@gmail.com
Cc: pgsql-docs@lists.postgresql.org
Subject: Re: Typo on tutorial window page
Date: Tue, 21 Jan 2025 12:39:25 -0500
Message-ID: <3359764.1737481165@sss.pgh.pa.us> (raw)
In-Reply-To: <173737973383.1070.1832752929070067441@wrigleys.postgresql.org>
References: <173737973383.1070.1832752929070067441@wrigleys.postgresql.org>
PG Doc comments form <noreply@postgresql.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
view thread (6+ messages) latest in thread
Message-ID: <3359764.1737481165@sss.pgh.pa.us>
Permalink: ../3359764.1737481165@sss.pgh.pa.us/
Also on: postgresql.org/message-id/3359764.1737481165@sss.pgh.pa.us
reply
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-docs@postgresql.org
Cc: tgl@sss.pgh.pa.us, oselemg@gmail.com, pgsql-docs@lists.postgresql.org
Subject: Re: Typo on tutorial window page
In-Reply-To: <3359764.1737481165@sss.pgh.pa.us>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox