Re: Should clients abort in case of server version mismatch ? [ subject modf: as they already warn ]

On 12/8/06, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> "Rajesh Kumar Mallah" <mallah(dot)rajesh(at)gmail(dot)com> writes:
> > IMHO for major version mismatch psql should not present the
> > user with a prompt at all as certain commands are most likely
> > not work.
>
> The analogy you're drawing with pg_dump is faulty. There are at least
> three good reasons for psql to be more forgiving of version mismatches
> than pg_dump is:

Overall there was no damage at all.

>
> 1. pg_dump is commonly run noninteractively (eg, from a cron job) where
> any mere warning will likely go unnoticed. So it has to raise a hard
> error to get the DBA's attention. psql's backslash commands are far
> less likely to be used noninteractively, and a failure is usually pretty
> obvious to a human user.

yep if the scope of problem is limited to \d commands *only* its a nonissue
(i was not knowing it). in most automations i think psql would only be acting
as a conduit for SQL commands. hence the concerns were not well founded.

Warm Regds
Mallah.

>
> 2. pg_dump is critical: if it dumps an unusable backup due to not
> understanding the system catalogs of a newer server, the DBA who needs
> that backup later will be badly screwed. psql's backslash commands,
> again, are not so critical.
>
> 3. psql offers a pretty decent amount of functionality even if some of
> its backslash commands don't work, whereas a dump that is wrong is worse
> than useless. So the use-case for operating with a version mismatch is
> much wider for psql.
>
> So I think we have the right tradeoffs in this regard now.
>
> regards, tom lane
>