Horton

Re: [patch] bit XOR aggregate functions

Vik Fearing <vik@postgresfriends.org>

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From: Vik Fearing <vik@postgresfriends.org>
To: Pavel Stehule <pavel.stehule@gmail.com>
Cc: "David G. Johnston" <david.g.johnston@gmail.com>, David Fetter <david@fetter.org>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Kyotaro Horiguchi <horikyota.ntt@gmail.com>, "bashtanov@imap.cc" <bashtanov@imap.cc>, "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
Date: 2021-03-07T10:28:55Z
Lists: pgsql-hackers 
On 3/7/21 11:24 AM, Pavel Stehule wrote:
>>
>> And so you are now mandating an ORDER BY on every query and in every
>> aggregate and/or window function.  Users will not like that at all.  I
>> certainly shan't.
>>
> 
> The mandatory ORDER BY clause should be necessary for operations when the
> result depends on the order. You need an order for calculation of median.
> And you don't need to know an order for average. More if the result is one
> number and is not possible to do a visual check of correctness (like
> median).

The syntax for median (percentile_cont(0.5)) already requires an order
by clause.  You are now requiring one on array_agg().
-- 
Vik Fearing

Commits

  1. Add bit_xor aggregate function