Re: pg_dump transaction's read-only mode

On Mon, Jan 21, 2013 at 8:00 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Pavan Deolasee <pavan(dot)deolasee(at)gmail(dot)com> writes:
>> On Sun, Jan 20, 2013 at 4:29 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> As submitted, this broke pg_dump for dumping from pre-8.0 servers.
>>> (7.4 didn't accept commas in SET TRANSACTION syntax, and versions
>>> before that didn't have the READ ONLY option at all.)
>
>> My bad. I did not realize that pg_dump is still supported for pre-8.0 releases.
>
> It supports servers back to 7.0. At some point we ought to consciously
> desupport old servers and pull out the corresponding code, but that
> needs to be an act of intention not omission ;-)
>
> (It's entirely likely that the 7.0 server I keep around for testing this
> is the last one in captivity anywhere. But IIRC, we've heard fairly
> recent reports of people still using 7.2. We'd have to desupport before
> 7.3 to save any meaningful amount of pg_dump code, so I'm not convinced
> it's time to pull the trigger on this quite yet.)

The final release of the PostgreSQL 7.3 series was stamped in January,
2008, at which point the most current release was PostgreSQL 8.2,
which is now itself EOL. Also, the original release of PostgreSQL 7.3
was in November of 2012, so we've also passed the ten-year mark for
that code. Both of those seem like reasonable yardsticks for saying
that we don't need to support that any more.

On a more practical level, if someone is trying to upgrade from
PostgreSQL 7.3 or older to a modern version, it's probably going to be
pretty hard for other reasons anyway. We change a few things in a
backward-incompatible fashion in every release, and over time those
add up. So I think anyone doing an upgrade from 7.3 probably has
their work cut out for them. I would likely advise someone in that
situation to consider an intermediate upgrade to 8.2 first, and then
go on to 9.2 from there.

All that having been said, I'm in no rush to drop the older code this
release. We have enough other things to do right now. But, it might
be something to consider for 9.4.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company