Re: Weird pg_dumpall bug?

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Peter Eisentraut <peter_e@gmx.net>
Cc: pgsql-hackers@postgresql.org, Stephen Frost <sfrost@snowman.net>, Christopher Kings-Lynne <chriskl@familyhealth.com.au>
Date: 2006-01-24T17:00:47Z
Lists: pgsql-hackers
Peter Eisentraut <peter_e@gmx.net> writes:
> Am Dienstag, 24. Januar 2006 15:44 schrieb Stephen Frost:
>> Have you got a suggestion on just how to fix it...?  Debian's
>> pg_upgradecluster bails out with an error when it discovers this
>> situation but I don't think it'd be sensible for pg_dump to do that...

> Why not?  If the backup cannot be made in a way such that the
> semantics of the restored database are the same, it shouldn't do it.

If you take a hard line on that position, then it's not necessary for
pg_dump to support cross-version operation at all, because no major
PG release is ever 100.0% compatible with the previous one.

What is actually required of pg_dump is that it produce the closest
approximation it can get to the old behavior within the context of the
new version's semantics.  I can easily cite half a dozen examples of
cases where we've applied this logic in previous versions.  I do not
see a reason to treat this case differently.  The difference between
a single role acting as both user and group and the prior behavior of
separate objects is certainly well within the "fuzz factor" that we've
allowed pg_dump to have in the past.

			regards, tom lane