Re: Re: [Pg-migrator-general] Composite types break pg_migrated tables

Bruce Momjian <bruce(at)momjian(dot)us> writes:
> Peter Eisentraut wrote:
>> That might be a bit excessive. As I understand it, arrays of built-in types
>> (e.g., int[]) should work fine. I suspect the majority of uses of arrays will
>> be with built-in types, so allowing that would help a significant portion of
>> installations.

> Agreed. I realized that last night, and have modified pg_migrator to
> test FirstNormalObjectId.

That's really the wrong thing. It's safe to assume OIDs below 10000
are portable across versions, because for them not to be would require
someone to have changed a hand assignment. However, OIDs between 10000
and 16K are assigned on-the-fly by initdb, and those are *not* likely
to be portable across versions. As an example, the rowtype for
pg_statistic has slightly different OIDs in 8.3 and 8.4. So if you
allow someone to port a database that is using a system catalog's
rowtype, it will fail. Admittedly that's not a real likely scenario,
but if you're going to have a check it should be accurate.

regards, tom lane