Re: pg_upgrade if 'postgres' database is dropped

* Bruce Momjian (bruce@momjian.us) wrote:
> Well, you would have to remove it _after_ you did the pg_upgrade.  Right
> now if you do a normal dump/restore upgrade, you also have to re-remove
> the postgres database.  We don't have any mechanism to drop a database
> as part of pg_dumpall's restore if it didn't exist in the old cluster.

Perhaps not, but it *could* be removed after the restore and all would
be well, yes?

> > Regarding pg_dumpall and pg_restore, I'm pretty sure both of those can
> > be configured to connect to other databases instead, including for
> > globals.
>
> Well, please show me the code, because the C code I showed you had the
> '\connect postgres' string hardcoded in there.

I guess there's a difference between "can be used and will work
correctly, but might create some extra garbage" and "can't be used at
all".  pg_dumpall has a -l option for connecting to whatever *existing*
database you have to pull the global data, and then it'll restore into a
clean initdb'd cluster, after which you could remove postgres.
Admittedly, if you initdb the cluster, drop postgres, and then try a
restore, it would fail.  Personally, I'm not a big fan of that (why
don't we use what was passed in to -l for that..?), but, practically,
it's not that big a deal.  I don't know many folks who are going to
restore a pg_dumpall dump into an existing configuration where they've
monkied with things (that could cause all kinds of other issues anyway,
role conflicts, etc).

If I understood correctly (perhaps I didn't..), is that pg_upgrade
doesn't have the pg_dumpall equivilant of the '-l' or '--database'
option, and that's what is at issue here.
Thanks,
    Stephen