On 10/6/23 11:08, David G. Johnston wrote:
On 10/6/23 08:45, Ron wrote:
> On 10/6/23 09:04, Andreas Kretschmer wrote:
>>
>>> Not sure how convincing that reasoning is, but it was at least
>>> thought about. I do agree with it as far as the default column
>>> list goes, but maybe we could allow explicit selection of these
>>> columns in COPY TO.
>>
>> sounds okay
>
> Nah. "The programmer -- and DBA -- on the Clapham omnibus" quite
> reasonably expects that COPY table_name TO (output)" copies all the
> columns listed in "\d table_name".
>
Yeah, I would agree.
Sure, but it doesn't. Mainly since copy's original design was intended to solve the dump/restore problem and it doesn't make sense to specify data for inbound generated data. So while we do have a POLA violation here the desirability to now fix it years later is basically zero. And the current behavior is at least defensible and consistent. And there is a very easy way to get the desired output making any change that much harder a sell.
At least it's explicitly mentioned in the docs that generated columns are excluded.
The error message maybe could use some help though, and if there isn't a hint maybe add one.
David J.
--
Born in Arizona, moved to Babylonia.