Search Postgresql Archives

Re: why generated columsn cannot be used in COPY TO?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 10/6/23 09:04, Andreas Kretschmer wrote:


Am 06.10.23 um 15:47 schrieb Tom Lane:
Luca Ferrari <fluca1978@xxxxxxxxx> writes:
I'm wondering why in COPY TO (file or program) I cannot use generated
columns: since I'm pushing data out of the table, why they are not
allowed?
There's a comment about that in copy.c:

  * We don't include generated columns in the generated full list and we don't
  * allow them to be specified explicitly.  They don't make sense for COPY
  * FROM, but we could possibly allow them for COPY TO.  But this way it's at
  * least ensured that whatever we copy out can be copied back in.

ha, as always: read the source ;-)


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".

https://en.wikipedia.org/wiki/Man_on_the_Clapham_omnibus
"The man on the Clapham omnibus is a hypothetical ordinary and reasonable person, used by the courts in English law where it is necessary to decide whether a party has acted as a reasonable person would – for example, in a civil action for negligence. The character is a reasonably educated, intelligent but nondescript person, against whom the defendant's conduct can be measured."

--
Born in Arizona, moved to Babylonia.

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Postgresql Jobs]     [Postgresql Admin]     [Postgresql Performance]     [Linux Clusters]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Databases]     [Postgresql & PHP]     [Yosemite]

  Powered by Linux