Re: Implementation DISTINCT for window aggregate function: SUM - Mailing list pgsql-hackers

From David Rowley
Subject Re: Implementation DISTINCT for window aggregate function: SUM
Date
Msg-id CAApHDvpPqApuv_i_GdZF2wP7LTUugP3OV2WeGW2Yr1uXYjQZrg@mail.gmail.com
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In response to Implementation DISTINCT for window aggregate function: SUM  (Eugen Konkov <kes-kes@yandex.ru>)
List pgsql-hackers
On Sat, 18 Apr 2020 at 23:47, Eugen Konkov <kes-kes@yandex.ru> wrote:
> select id, amount, sum(DISTINCT amount) over () as total
>   from xx;

> Why this is not possible in PG?

Mainly because nobody has committed anything to implement it yet.

> Why Window-specific functions do not allow DISTINCT to be used within the function argument list.?
> Which problems are exists?

There are some details in [1] which you might be interested in.

David

[1]
https://www.postgresql.org/message-id/flat/CAN1Pwonf4waD%2BPWkEFK8ANLua8fPjZ4DmV%2BhixO62%2BLiR8gwaA%40mail.gmail.com



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