Subject: Re: Adding Support for Copy callback functionality on COPY TO api
To: "Sanaba, Bilva" <bilvas@amazon.com>,
 "pgsql-hackers@postgresql.org" <pgsql-hackers@postgresql.org>
References: <253C21D1-FCEB-41D9-A2AF-E6517015B7D7@amazon.com>
From: "Andrey V. Lepikhov" <a.lepikhov@postgrespro.ru>
Organization: Postgres Professional
Message-ID: <ac458ac3-3223-9a9d-1e8b-2e7fa3b6b32e@postgrespro.ru>
Date: Wed, 30 Sep 2020 13:48:12 +0500
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On 7/2/20 2:41 AM, Sanaba, Bilva wrote:
> Hi hackers,
> 
> Currently, the COPY TO api does not support callback functions, while 
> the COPY FROM api does. The COPY TO code does, however, include 
> placeholders for supporting callbacks in the future.
> 
> Rounding out the support of callback functions to both could be very 
> beneficial for extension development. In particular, supporting 
> callbacks for COPY TO will allow developers to utilize the preexisting 
> command in order to create tools that give users more support for moving 
> data for storage, backup, analytics, etc.
> 
> We are aiming to get the support in core PostgreSQL and add COPY TO 
> callback support in the next commitfest.The attached patch contains a 
> change to COPY TO api to support callbacks.
> 
Your code almost exactly the same as proposed in [1] as part of 'Fast 
COPY FROM' command. But it seems there are differences.

[1] 
https://www.postgresql.org/message-id/flat/3d0909dc-3691-a576-208a-90986e55489f%40postgrespro.ru

-- 
regards,
Andrey Lepikhov
Postgres Professional