Re: Transactional sequence stuff breaks pg_upgrade

Andres Freund <andres(at)anarazel(dot)de> writes:
> On 2017-06-12 17:35:37 -0400, Tom Lane wrote:
>> I thought about trying to insert an assert in GetNewOidWithIndex to
>> ensure that no type OIDs are selected automatically during upgrade,
>> but it seemed a bit too complicated. Might be a good idea to figure
>> it out though, unless you have an idea for removing that requirement.

> I think the only type oids assigned during pg_upgrade are the oids for
> toast type types, right?

Perhaps that was a problem once, but it isn't now; see
binary_upgrade_set_next_toast_pg_type_oid().

In fact, we get through the pg_upgrade regression test with the attached
patch, and I really think we ought to commit it.

Having said that, I wouldn't mind trying to reduce the catalog overhead
for toast tables in v11 or beyond.

> a) Do not create a corresponding composite type for toast tables. Not
> super pretty, but I doubt it'd be a huge issue.

I suspect there are places that assume all tables have type OIDs.

> b) Use *one* composite type for all of the toast tables. That'd not be
> entirely trivial because of pg_type.typrelid.

That might work, with some klugery. Peter might have some insight about
this --- I'm not sure whether the CREATE TABLE OF TYPE syntax shares
a type OID across all the tables.

regards, tom lane