Re: raw output from copy

On 07/02/2015 09:43 AM, Simon Riggs wrote:
> On 2 July 2015 at 14:02, Andrew Dunstan <andrew@dunslane.net 
> <mailto:andrew@dunslane.net>> wrote:
>
>
>     Please don't top-post on the PostgreSQL lists. You've been around
>     here long enough to know that bottom posting is our custom.
>
>     I posted a patch for this in 2013 at
>     <http://www.postgresql.org/message-id/50F2FA92.9040000@dunslane.net>
>     but it can apply to a SELECT, and doesn't need COPY. Nobody seemed
>     very interested, so I dropped it. Apparently people now want
>     something along these lines, which is good.
>
>
> It's a shame that both solutions are restricted to either COPY or psql.
>
> Both of those are working on suggestions from Tom, so there is no 
> history of preference there.
>
> Can we have both please, gentlemen?
>
> If we implemented Andrew's solution, how would we request it in a COPY 
> statement? Seems like we would want the RAW format keyword anyway.
>
>


What's the use case? My original motivation was that I had a function 
that returned a bytea (it was a PDF in fact) that I wanted to be able to 
write to a file. Of course, this is easy enough to do with a client 
library like perl's DBD::Pg, but it seems sad to have to resort to that 
for something so simple.

My original suggestion 
(<http://www.postgresql.org/message-id/4EA1B83B.2050605@pgexperts.com>) 
was to invent a \bcopy command.

I don't have a problem in building in a RAW mode for copy, but we'll 
still need to teach psql how to deal with it.

Another case where it could be useful is JSON - so we can avoid having 
to play tricks like 
<http://adpgtech.blogspot.com/2014/09/importing-json-data.html>. Similar 
considerations probably apply to XML, and the tricks are less guaranteed 
to work.

cheers

andrew