Re: [PATCH] COPY .. COMPRESSED

On Tue, Jan 15, 2013 at 2:53 PM, Stephen Frost <sfrost(at)snowman(dot)net> wrote:
> The popen patch doesn't support the '|compression-binary' option through
> the FE protocol. Even if it did, it would only be available for
> superusers as we can't allow regular users to run arbitrary commands on
> the server-side.

That points towards a fix that involves having a set of non-arbitrary commands
that we allow plain users to use.

Hmm. There's an interesting thought...

How about having a "pg_filters" table in pg_catalog which allows capturing
labels and names of known-to-be-safe binary filters:

insert into pg_filters (label, location)
values
('zcat', '/usr/bin/zcat'),
('bzip2', '/usr/bin/bzip2'),
('bunzip2', '/usr/bin/bunzip2');

And then having some capability to grant permissions to roles to use
these filters.

That's not a "version 1" capability... Suppose we have, in 9.3, that there are
direct references to "|/usr/bin/zcat" (and such), and then hope, in
9.4, to tease
this out to be a non-superuser-capable facility via the above pg_filters?

These filters should be useful for FDWs as well as for COPY.
--
When confronted by a difficult problem, solve it by reducing it to the
question, "How would the Lone Ranger handle this?"