Re: Disable OpenSSL compression

On Wed, Nov 09, 2011 at 05:26:14PM -0500, Tom Lane wrote:
> Magnus Hagander <magnus@hagander.net> writes:
> > On Wednesday, November 9, 2011, Albe Laurenz wrote:
> >> Is the following proposal acceptable:
> >> 
> >> - Add a GUC ssl_compression, defaulting to "on".
> >> - Add a client option "sslcompression" and an environment variable
> >> PGSSLCOMPRESSION, defaulting to "1".
> 
> > Seems like the reasonable thing, yes.
> 
> A GUC is entirely, completely, 100% the wrong answer.  It has no way to
> deal with the fact that some clients may need compression and others
> not.
> 
> It should be a client option, full stop.  The fact that that will be
> more work to implement does not make "kluge it at the server" the right
> answer.

Assuming the GUC is PGC_BACKEND or better, what is the distinction beyond the
cosmetic "sslcompression=off" vs. "options='-c ssl_compression=off'"?

Does OpenSSL respect changes to this setting during a connection's lifetime?  If
so, we could offer a PGC_USERSET GUC, enabling the client to even alternate use
of compression within a single session.