Message-ID: <bcd7b41fe5c31e489dbf2b84f71e54435b34594b.camel@cybertec.at>
Subject: Re: Todo item: distinct clause - guidance
From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Ankit Kumar Pandey <itsankitkp@gmail.com>,
	pgsql-novice@lists.postgresql.org
Date: Sun, 06 Nov 2022 20:12:58 +0100
In-Reply-To: <fa46c213-c8a8-1123-d212-10db7919cd8a@gmail.com>
References: <fa46c213-c8a8-1123-d212-10db7919cd8a@gmail.com>
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On Sun, 2022-11-06 at 18:39 +0530, Ankit Kumar Pandey wrote:
> I was looking for some to-do item to pick up and came across 'Implement DISTINCT
> clause in window aggregates'. Can someone pleaseelaborate what is expectation here?
> Do feature request still exists as DISTINCT worked as expected if we try functions
> like avg(distinct col)?

Whis is about window functions, like

  WITH q(a,b) AS (VALUES (1, 1), (1, 1), (2, 1))
  SELECT *,
         count(DISTINCT a) OVER (PARTITION BY b)
  FROM q;

  ERROR:  DISTINCT is not implemented for window functions
  LINE 3:        count(DISTINCT a) OVER (PARTITION BY b)
                 ^

Yours,
Laurenz Albe