Re: libpq compression (part 3)

On Fri, May 17, 2024 at 1:53 PM Jacob Burroughs
<jburroughs(at)instructure(dot)com> wrote:
> New proposal, predicated on the assumption that if you enable
> compression you are ok with the client picking whatever level they
> want. At least with the currently enabled algorithms I don't think
> any of them are so insane that they would knock over a server or
> anything, and in general postgres servers are usually connected to by
> clients that the server admin has some channel to talk to (after all
> they somehow had to get access to log in to the server in the first
> place) if they are doing something wasteful, given that a client can
> do a lot worse things than enable aggressive compression by writing
> bad queries.

We're talking about a transport-level option, though -- I thought the
proposal enabled compression before authentication completed? Or has
that changed?

(I'm suspicious of arguments that begin "well you can already do bad
things", anyway... It seems like there's a meaningful difference
between consuming resources running a parsed query and consuming
resources trying to figure out what the parsed query is. I don't know
if the solution is locking in a compression level, or something else;
maybe they're both reasonably mitigated in the same way. I haven't
really looked into zip bombs much.)

--Jacob