Re: proposal: psql concise mode

Josh Kupershmidt <schmiddy(at)gmail(dot)com> writes:
> FWIW, I just played around with 7.4 and 7.3 servers. (I had some bad
> memories of the older tarballs not building, but that must have been
> only on OS X -- I can build at least back to 7.3 on this Ubuntu 11.04
> machine.)

> Most meta-commands worked alright on 7.4, or at least failed
> gracefully. The ones I saw which failed unexpectedly were \sf and \ef,
> which complained:
> ERROR: function pg_catalog.pg_get_functiondef(integer) does not exist

> I think we need a server version check for these two meta-commands,
> unless someone cares to make them work on < 8.4, trivial patch
> attached.

Agreed, we should check that. Will commit.

> As I suggested, many more unexpected failures (e.g. \dnS+) pop up when
> talking to a 7.3 server. It's not a big deal, but it'd be nice if we
> could instead error out with a "sorry, we're too lazy to try to
> support 7.3" on the meta-commands which fail thusly, and make the
> various "else" clauses more explicit about just how far back their
> support really goes.

Probably not worth the trouble ... how many pre-7.4 servers are still in
the wild, and of those, how many might somebody try to talk to with a
modern psql?

The more realistic direction of future change, I think, is that we move
up the cutoff version so we can take out some code, rather than add
more. At the moment I'd find it a hard sell to drop support for 8.1 or
later; so maybe there's not enough removable code to make it worth any
effort. But in a few more years it'd be worth doing.

What *would* be worth doing today, IMO, is ripping out pg_dump's support
for servers older than 7.3 or 7.4; in particular getting rid of its
kluges for server versions without pg_depend info.

regards, tom lane