COPY Hacks (WAS: RE: Postgresql vs SQLserver for this application ?)

This thread seems to be focusing in on COPY efficiency,
I'd like to ask something I got no answer to, a few months ago.

Using COPY ... FROM STDIN via the Perl DBI (DBD::Pg) interface,
I accidentally strung together several \n-terminated input lines,
and sent them to the server with a single "putline".

To my (happy) surprise, I ended up with exactly that number of rows
in the target table.

Is this a bug? Is this fundamental to the protocol?

Since it hasn't been documented (but then, "endcopy" isn't documented),
I've been shy of investing in perf testing such mass copy calls.
But, if it DOES work, it should be reducing the number of network
roundtrips.

So. Is it a feechur? Worth stress-testing? Could be VERY cool.

--
"Dreams come true, not free."