Re: pg_upgrade if 'postgres' database is dropped

On Tue, Nov 1, 2011 at 2:49 PM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> Robert Haas wrote:
>> >> > It turns out there was only one place that expected a 1-1 mapping of old
>> >> > and new databases (file transfer), so I just modified that code to allow
>> >> > skipping a database in the new cluster that didn't exist in the old
>> >> > cluster.
>> >>
>> >> Urp. ?But that means that if someone has any data in that database,
>> >> pg_upgrade will basically eat it. ?That does not seem like a step
>> >> forward.
>> >
>> > Please clarify? ?We already check that all the new cluster databases are
>> > empty, so we are effectively skipping the transfering of files into
>> > empty new cluster databases. ?It processes all old cluster databases and
>> > forces a new cluster match --- it is only empty new cluster database
>> > that are being skipped.
>>
>> Aren't you saying that if a postgres database exists in the old
>> database (and potentially contains data) but is missing in the new
>> database, we'll just fail to migrate it?
>
> No, the reverse.  If the 'postgres' database exists in the new cluster,
> but not in the old, we allow it to upgrade (we skip over the 'postgres'
> database in the new cluster use the loop in the patch).

Oh, OK. That seems fine - in fact, that seems perfect.

> Unless I am missing something.  Did you see something odd in the patch
> or in my wording?

Your wording confused me, but on further review I think I'm just
easily confused.

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