To: Andreas Pflug <pgadmin@pse-consulting.de>
cc: "Joshua D. Drake" <jd@commandprompt.com>, pgsql-hackers@postgresql.org
Subject: Re: Possible TODO item: copy to/from pipe 
In-reply-to: <447DD1D7.20001@pse-consulting.de> 
References: <12436.1149087794@sss.pgh.pa.us>
	<447DB844.6010507@pse-consulting.de>
	<447DB910.2020607@pse-consulting.de>
	<13208.1149093007@sss.pgh.pa.us>
	<447DCFAF.4070308@commandprompt.com>
	<447DD1D7.20001@pse-consulting.de>
Comments: In-reply-to Andreas Pflug <pgadmin@pse-consulting.de>
	message dated "Wed, 31 May 2006 19:26:47 +0200"
Date: Wed, 31 May 2006 16:10:32 -0400
Message-ID: <15060.1149106232@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Andreas Pflug <pgadmin@pse-consulting.de> writes:
> My COPY WITH COMPRESSION is not the same as taking a copy file and 
> zipping it; it creates a copy file with BinarySignature that has 
> compressed bytes in the data part, thus it can be handled by any client 
> app that can stream binary copy files from/to the server.

If you mean you're compressing each data field separately, that's surely
a very bad idea.  If you mean you're compressing everything except the
file header, I fail to see the value.  Binary is binary.  I *seriously*
doubt there are clients out there that look for a PGCOPY header before
deciding whether to send the file to the server or not.  And a client
that did know that much about a PGCOPY file would likely spit up on a
critical flag it didn't recognize, anyway.

			regards, tom lane