Re: pg_migrator issue with contrib

Tom Lane wrote:
> Magnus Hagander <magnus(at)hagander(dot)net> writes:
>> As long as PostGIS is the same version in both of them, is pg_migrator
>> is likely to work? (one can always run the PostGIS upgrade as a separate
>> step)
>
> There was just some discussion about that on postgis-devel. I think the
> conclusion was that you would have to do the PostGIS update as a
> separate step. They intend to support both 1.3.x and 1.4.x on current
> versions of Postgres for some time, so in principle you could do it in
> either order.

Doing them as two steps is totally fine with me, because IIRC the
PostGIS upgrades generally don't require hours and hours of downtime.

>>> Could pg_migrator detect usage of "objects" oids (data types in
>>> relation, index opclass, ...) that are unknown to be in the standard
>>> -core + contrib distribution, and quit trying to upgrade the cluster in
>>> this case, telling the user his database is not supported?
>
>> +1 on this.
>
>> Or at least, have it exit and say "if you know that these things are
>> reasonably safe, run pg_migrator again with --force" or something like that.
>
> I don't think that anything in that line is going to be helpful.
> What it will lead to is people mindlessly using --force (cf our
> bad experiences with -i for pg_dump). If you can't give a *useful*
> ie trustworthy warning/error, issuing a useless one is not a good
> substitute.

Well, in that case, error out would be a better option than doing it and
probably fail later. And have a --force option available, but don't
suggest it.

//Magnus