Re: pg_dump transaction's read-only mode

On 01/21/2013 08:45 PM, Tom Lane wrote:
> Stefan Kaltenbrunner <stefan(at)kaltenbrunner(dot)cc> writes:
>> On 01/21/2013 02:00 PM, Tom Lane wrote:
>>> (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.)
>
>> old versions are still alive - just yesterday we had someone on IRC
>> trying to build 7.1.3 on a modern ubuntu installation because he has an
>> old app depending on it., and especially 7.2 shows up regulary as well.
>
>> If the effort to keep pg_dump support for those alive is not too bad, we
>> should try to support them as long as we can.
>
> Of course, the counter-argument is that people who are still using those
> versions are probably not going to be interested in upgrading to a
> modern version anyway. Or if they are, dumping with their existing
> version of pg_dump is likely to not be much worse than dumping with the
> target version's pg_dump --- as Robert mentioned upthread, if you're
> migrating from such an old version you're in for a lot of compatibility
> issues anyhow, most of which pg_dump can't save you from.

sure - but having at least an easy way to properly get your schema and
data over from such an old version helps. That "only" leaves you with
the compatibility issues in the app - having to do both would be worse.

>
> Having said that, I'm not in a hurry to pull pg_dump support for old
> versions. But we can't keep it up forever. In particular, once that
> old HPUX box dies, I'm not likely to want to try to get 7.0 to compile
> on a newer box just so I can keep checking pg_dump compatibility.

yeah I'm not saying we need to keep this forever, if we say drop
everyting including 7.3 with 9.4 that would mean that we would "support"
direct upgrades using pg_dump for over 10 years (7.3s last supported
release was in january 2008 and assuming we get 9.3 out the door this
year) for indirekt upgrades (ie using one intermediate step) we would be
talking more like 15-20 years if we keep the current level of backwards
compatibility - this seems plenty enough for me...

Stefan