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

From Pavel Stehule
Subject Re: Re: csv format for psql
Date
Msg-id CAFj8pRD7UtP299cnq3+p0=AUdJdxMFObZpyo2qY3=uNrFMaqjA@mail.gmail.com
Whole thread Raw
In response to Re: Re: csv format for psql  (Fabien COELHO <coelho@cri.ensmp.fr>)
Responses Re: csv format for psql  ("David G. Johnston" <david.g.johnston@gmail.com>)
List pgsql-hackers


2018-03-28 10:24 GMT+02:00 Fabien COELHO <coelho@cri.ensmp.fr>:

Hello Pavel,

I'd like to convince you to compromise, because otherwise I'm afraid we
will not get this feature.

[...]

The only no-surprise, no-behavioral-change, alternative I see is to have a
csv-specific fieldsep. I'm not keen on that one because it is yet another
variable, one has to remember it, and then it asks the question about
recordsep... and I think there are already too many parameters, and more is
not desirable, although I probably could live with that if I can live with
"fieldsep_zero":-)


I don't share your opinion so introduction csv-specific fieldsep is
surprise less. Current design is wrong - this thread is a evidence.

Wrong is too strong a word. Current design is not perfect, sure. Proposed alternatives are somehow worse, at least to some people mind, which explains why we arrived on this version after a few iterations.

And if we introduce csv-specific fieldsep, then we multiply this wrong design. The fix in this direction is renaming fieldsep to fieldsep-unaliagn - but it is probably too big change too. So this design is nothing what I can mark as good solution.

Good, we somehow agree on something!

I can live with because it is much better than using pipe as separator for csv, and because real impact is small - for almost people it will be invisible - but have not good feeling from it.

Are there some possible alternatives?

Given the date and the fact that the cf end is 3 days away, the proposed short term alternative is Daniel's version, that I feel is reasonable. Ok, people have to do two pset to get comma-separated csv, otherwise they get pipe-separated csv in one pset.

I dislike the last Daniel's design. I am sorry.


You could compromise on that for now, and submit an improvement patch for a later version if you wish.

I am able to accept csv specific field sep independent on unaligned field sep.

I have not any other idea. And there is not any good (acceptable) ideas. It is hard to expect so there will be change next year. This space is small, and there are not too much possible variants. We checked all possibility without any agreement.
 

Otherwise, ISTM that the current result of this thread is that there will be no simple CSV in pg11:-(

Can be. If there is not good enough solution now. If we merge it now, then will be hard to change it due possible compatibility issues.
 

Or maybe I can mark Daniel's latest version as "ready" and point out that there is some disagreement on the thread, so it is not a full consensus. Then a committer can decide whether it is better in like that or that it should be put back in some design stage, possibly with their preference wrt to the kind of solution they think best.

You can do it. But from my view the Daniel's latest version (with respect to his work) is the worst variant :(. So I am against to commit this version.

Regards

Pavel




--
Fabien.

pgsql-hackers by date:

Previous
From: Jesper Pedersen
Date:
Subject: Re: [HACKERS] path toward faster partition pruning
Next
From: Teodor Sigaev
Date:
Subject: Re: [HACKERS] GSoC 2017: weekly progress reports (week 6)