Обсуждение: Weird pg_dumpall bug?
I did a dump of a 7.4.11 database using the 8.1.2 pg_dumpall. I got this at the top of the dump: ... ... CREATE ROLE support; ALTER ROLE support WITH NOSUPERUSER INHERIT NOCREATEROLE NOCREATEDB LOGIN PASSWORD 'md5xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'; ... ... CREATE ROLE support; ALTER ROLE support WITH NOSUPERUSER INHERIT NOCREATEROLE NOCREATEDB NOLOGIN; ... ... It dumped the "support" role twice! Any ideas? Hmmmm...actually. It's because I have a user called 'support' and a group called 'support'. Seems like it needs a fix... Chris
* Christopher Kings-Lynne (chriskl@familyhealth.com.au) wrote:
> Hmmmm...actually. It's because I have a user called 'support' and a
> group called 'support'.
>
> Seems like it needs a fix...
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...
Thanks,
Stephen
On Tue, 2006-01-24 at 09:44 -0500, Stephen Frost wrote: > * Christopher Kings-Lynne (chriskl@familyhealth.com.au) wrote: > > Hmmmm...actually. It's because I have a user called 'support' and a > > group called 'support'. > > > > Seems like it needs a fix... > > 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... > How about an option to map groups whose names conflict with user names using a prefix mechanism? e.g. --map-conflicting-groups=gr_ Then in Christopher's example his support group would become the role gr_support. Just a thought. cheers andrew
Christopher Kings-Lynne <chriskl@familyhealth.com.au> writes:
> Hmmmm...actually. It's because I have a user called 'support' and a
> group called 'support'.
This was discussed already. It's a corner case we didn't really think
about while designing roles. It's possible to support this: the group
and the user will now really be the same entity, ie a role that has both
its own login privileges and members. However pg_dump isn't doing the
right things to make the old situation morph into the new one. Want to
write a patch?
regards, tom lane
On Tue, 2006-01-24 at 10:05 -0500, Tom Lane wrote: > Christopher Kings-Lynne <chriskl@familyhealth.com.au> writes: > > Hmmmm...actually. It's because I have a user called 'support' and a > > group called 'support'. > > It's possible to support this: the group > and the user will now really be the same entity, ie a role that has both > its own login privileges and members. > Assuming you actually want to unify the two objects. That might well be the common case, but will it always be true? cheers andrew
Andrew Dunstan <andrew@dunslane.net> writes:
> On Tue, 2006-01-24 at 10:05 -0500, Tom Lane wrote:
>> It's possible to support this: the group
>> and the user will now really be the same entity, ie a role that has both
>> its own login privileges and members.
> Assuming you actually want to unify the two objects. That might well be
> the common case, but will it always be true?
As compared to what? I didn't like the notion of auto-renaming one of
the roles, if that's what you're suggesting. That seems well outside
pg_dump's charter.
regards, tom lane
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. -- Peter Eisentraut http://developer.postgresql.org/~petere/
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
> How about an option to map groups whose names conflict with user names > using a prefix mechanism? > > e.g. --map-conflicting-groups=gr_ > > Then in Christopher's example his support group would become the role > gr_support. No bad, have to change some application code then as well... Chris
On Tue, Jan 24, 2006 at 10:42:17AM -0500, Tom Lane wrote: > Andrew Dunstan <andrew@dunslane.net> writes: > > On Tue, 2006-01-24 at 10:05 -0500, Tom Lane wrote: > >> It's possible to support this: the group > >> and the user will now really be the same entity, ie a role that has both > >> its own login privileges and members. > > > Assuming you actually want to unify the two objects. That might well be > > the common case, but will it always be true? > > As compared to what? I didn't like the notion of auto-renaming one of > the roles, if that's what you're suggesting. That seems well outside > pg_dump's charter. If you want something renamed, you can handle that case by just renaming it before you do the dump, but it would be nice if pg_dump would raise a nice big warning when this condition exists so you're aware of it. Or maybe even refuse to run unless you supply some command line option to over-ride. I don't think we should morph the two together by default either, because that's very possibly not what the user originally intended. -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461