Date: Fri, 15 Mar 2024 17:37:54 +0900 (JST)
Message-Id: <20240315.173754.2049843193122381085.kou@clear-code.com>
To: jian.universality@gmail.com
Cc: michael@paquier.xyz, andres@anarazel.de, sawada.mshk@gmail.com,
 zhjwpku@gmail.com, andrew@dunslane.net, nathandbossart@gmail.com,
 pgsql-hackers@postgresql.org
Subject: Re: Make COPY format extendable: Extract COPY TO format
 implementations
From: Sutou Kouhei <kou@clear-code.com>
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Hi,

In <CACJufxFbffGaxW1LiTNEQAPcuvP1s7GL1Ghi--kbSqsjwh7XeA@mail.gmail.com>
  "Re: Make COPY format extendable: Extract COPY TO format implementations" on Wed, 13 Mar 2024 16:00:46 +0800,
  jian he <jian.universality@gmail.com> wrote:

>> More use cases will help us which callbacks are needed. We
>> will be able to collect more use cases by providing basic
>> callbacks.

> Let's say the customized format is "csv1", but it is just analogous to
> the csv format.
> people should be able to create an extension, with serval C functions,
> then they can do `copy (select 1 ) to stdout (format 'csv1');`
> but the output will be exact same as `copy (select 1 ) to stdout
> (format 'csv');`

Thanks for sharing one use case but I think that we need
real-world use cases to consider our APIs.

For example, JSON support that is currently discussing in
another thread is a real-world use case. My Apache Arrow
support is also another real-world use case.


Thanks,
-- 
kou