Re: csv format for psql - Mailing list pgsql-hackers

From Michael Paquier
Subject Re: csv format for psql
Date
Msg-id 20181109234414.GA2071@paquier.xyz
Whole thread Raw
In response to Re: csv format for psql  ("Daniel Verite" <daniel@manitou-mail.org>)
Responses Re: csv format for psql  ("Daniel Verite" <daniel@manitou-mail.org>)
Re: csv format for psql  ("David G. Johnston" <david.g.johnston@gmail.com>)
Re: csv format for psql  (Fabien COELHO <coelho@cri.ensmp.fr>)
List pgsql-hackers
On Fri, Nov 09, 2018 at 05:28:07PM +0100, Daniel Verite wrote:
> But again COPY is concerned with importing the data that preexists,
> even if it's weird, whereas a psql output formats are not.

Hm.  I checked the contents of the patch in details which provide output
consistent with COPY, but after looking at the global picture I am
getting cold feet on this patch for a couple of reasons:
- This stuff adds new code paths in the frontend mimicking what the
backend already does for years, both doing the same thing.
- There are already three ways to fetch data in this format with COPY,
\copy and file_fdw, with all three using the same code paths for option
validations (I can see the arguments at the top of the thread for which
COPY SELECT can actually do everything you want with?).
- The experience is confusing, as the psql format uses different options
than the backend to do the same things:
-- tuples_only instead of HEADER.
-- fieldsep_csv instead of DELIMITER
-- null is an equivalent of the one with the same name, which is
actually consistent.
-- encoding is also an equivalent of ENCODING.
-- and all the others missing.
That looks like a lot.
--
Michael

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