Re: BUG #1814: Cancelling a CLUSTER changes the OID counter

On 8/8/05, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> Uh, does the same thing happen if you *don't* cancel it?
>

Yes. In that case, it change the OID counter to the maximum OID in
the table if the OID counter was less than the maximum. This is only
a problem when the OID counter has wrapped because until then there
are no OID higher than the counter. I have verified it with a couple
of different tables different maximum OID; the counter went from 28
million, to 690 million, to 4286 million, to 4294 million.

> It looks to me like this could possibly happen due to CheckMaxObjectId()
> being applied to each OID found in the existing table.
>
> CheckMaxObjectId was always a kluge, and I'm not sure that it still has
> any redeeming social value at all. Can anyone think of a good reason
> to keep it?
>

From looking in the code, I am pretty sure CheckMaxObjectId is the
culprit. It sets the nextOID to the oid in the row if the
assigned_oid is greater than the nextOID.

We are using PostgreSQL 7.4.6 but it looks like the same code is in 8.0.3.

- Ian