Re: New "raw" COPY format

On Wed, Oct 16, 2024, at 18:04, Jacob Champion wrote:
> A hypothetical type whose text representation can contain '\r' but not
> '\n' still can't be unambiguously round-tripped under this scheme:
> COPY FROM will see the "mixed" line endings and complain, even though
> there's no ambiguity.

Yeah, that's quite an ugly limitation.

> Maybe no one will run into that problem in practice? But if they did,
> I think that'd be a pretty frustrating limitation. It'd be nice to
> override the behavior, to change it from "do what you think I mean" to
> "do what I say".

That would be nice.

>> That's an interesting idea that would provide more flexibility,
>> though, at the cost of complicating things by overloading the meaning
>> of DELIMITER.
>
> I think that'd be a docs issue rather than a conceptual one, though...
> it's still a delimiter. I wouldn't really expect end-user confusion.

Yeah, I meant the docs, but that's probably fine,
we could just add <note> to DELIMITER.

>> What I found appealing with the idea of a new COPY format,
>> was that instead of overloading the existing options
>> with more complexity, a new format wouldn't need to affect
>> the existing options, and the new format could be explained
>> separately, without making things worse for users not
>> using this format.
>
> I agree that we should not touch the existing formats. If
> RAW/SINGLE/whatever needed a multibyte line delimiter, I'm not
> proposing that the other formats should change.

Right, I didn't think you did either, I meant overloading the existing
options, from a docs perspective.

But I agree it's probably fine if we just overload DELIMITER in the docs,
that should be possible to explain in a pedagogic way,
without causing confusion.

/Joel