Message-ID: <4FD9E70B.9040607@timbira.com>
Date: Thu, 14 Jun 2012 10:28:43 -0300
From: Euler Taveira <euler@timbira.com>
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To: Tom Lane <tgl@sss.pgh.pa.us>
CC: Pgsql Hackers <pgsql-hackers@postgresql.org>
Subject: Re: libpq compression
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On 14-06-2012 02:19, Tom Lane wrote:
> I still think that pushing this off to openssl (not an ssh tunnel, but
> the underlying transport library) would be an adequate solution.
> If you are shoving data over a connection that is long enough to need
> compression, the odds that every bit of it is trustworthy seem pretty
> small, so you need encryption too.
> 
I don't want to pay the SSL connection overhead. Also I just want compression,
encryption is not required. OpenSSL give us encryption with/without
compression; we need an option to obtain compression in non-SSL connections.

> We do need the ability to tell openssl to use compression.  We don't
> need to implement it ourselves, nor to bring a bunch of new library
> dependencies into our builds.  I especially think that importing bzip2
> is a pretty bad idea --- it's not only a new dependency, but bzip2's
> compression versus speed tradeoff is entirely inappropriate for this
> use-case.
> 
I see, the idea is that bzip2 would be a compiled-in option (not enabled by
default) just to give another compression option. I don't have a strong
opinion about including it as another dependency. We already depend on zlib
and implementing compression using it won't add another dependency.

What do you think about adding a hook at libpq to load an extension that does
the compression? That way we don't add another dependency at libpq and also a
lot of extensions could be coded to cover a variety of algorithms without
putting us in trouble because of patent infringement.


-- 
   Euler Taveira de Oliveira - Timbira       http://www.timbira.com.br/
   PostgreSQL: Consultoria, Desenvolvimento, Suporte 24x7 e Treinamento