Re: Re: new set of psql patches for loading (saving) data from (to) text, binary files

2017-04-06 3:34 GMT+02:00 Stephen Frost <sfrost(at)snowman(dot)net>:

> Andres,
>
> * Andres Freund (andres(at)anarazel(dot)de) wrote:
> > On 2017-04-05 21:07:59 -0400, Stephen Frost wrote:
> > > * Andres Freund (andres(at)anarazel(dot)de) wrote:
> > > > I don't yet have a good idea how to deal with moving individual cells
> > > > into files, so they can be loaded. One approach would be to to have
> > > > something like
> > > >
> > > > \storequeryresult filename_template.%row.%column
> > > >
> > > > which'd then print the current query buffer into the relevant file
> after
> > > > doing replacement on %row and %column.
> > >
> > > I don't actually agree that there's a problem having the output from a
> > > query stored direclty in binary form into a single file. The above
> > > approach seems to imply that every binary result must go into an
> > > independent file, and perhaps that would be useful in some cases, but I
> > > don't see it as required.
> >
> > Well, it'd not be enforced - it'd depend on your template. But for a
> > lot of types of files, it'd not make sense to store multiple
> > columns/rows in file. Particularly for ones where printing them out to
> > files is actually meaningful (i.e. binary ones).
>
> Having the template not require the row/column place-holders included
> strikes me as more likely to be confusing. My initial thinking around
> this was that users who actually want independent files would simply
> issue independent queries, while users who want to take a bunch of int4
> columns and dump them into a single binary file would be able to do so
> easily.
>
> I'm not against adding the ability for a single query result to be saved
> into independent files, but it strikes me as feature creep on this basic
> capability. Further, I don't see any particular reason why splitting up
> the output from a query into multiple files is only relevant for binary
> data.
>

The files can be simply joined together outside psql

Personally I prefer relation type: single field, single file in special g
command - because I can simply off all formatting and result should be
correct every time.

Stephen, have you some use case for your request?

Regards

Pavel

> Thanks!
>
> Stephen
>