Re: Re: [GENERAL] pg_upgrade fails, "mismatch of relation OID" - 9.1.9 to 9.2.4

On Thu, May  9, 2013 at 05:11:43PM -0400, Tom Lane wrote:
> Bruce Momjian <bruce@momjian.us> writes:
> > OK, that's progress.  Having received the table schema privately via
> > email, I see several 'character varying(40)' fields in the schema.  So
> > the question is how was this table able to get away without a TOAST
> > table in 9.1, while 9.2 created one for an empty table?  Ideas?
> 
> AFAICT the needs_toast_table() logic is identical between 9.1 and 9.2,
> so it seems like it must have something to do with an odd ALTER TABLE
> history in the source database.  It's hard to think what, however.
> 
> In any case, it seems like pg_upgrade ought to have a strategy for
> dealing with tables acquiring toast tables like this, since if we
> ever do tweak the needs_toast_table() logic, or for instance do
> something like deciding to support 6-byte UTF8 codes, we're going
> to face such cases.  I dunno exactly how we might deal with it though...

Well, pg_upgrade operates in super-paranoid mode, so if we relax this,
it could potentially allow silent upgrade failures.  I realize
eventually we will need to deal with this, but I would prefer to delay
that.

Also, I added code in PG 9.1 to allow the old/new clusters to have
identical OID layouts, so this would certainly complicate the code;  see
info.c::gen_db_file_maps() for the check that is failing, and you can
see the 1:1 relationship.  It was done in this commit:
commit 002c105a0706bd1c1e939fe0f47ecdceeae6c52dAuthor: Bruce Momjian <bruce@momjian.us>Date:   Sat Jan 8 13:44:44 2011
-0500   In pg_upgrade, remove functions that did sequential array scans looking    up relations, but rather order
old/newrelations and use the same array    index value for both.  This should speed up pg_upgrade for databases    with
manyrelations.
 

FYI, historically we have fixed TOAST table creation issues in pg_dump.

Evan, is the 9.1 cluster loaded into 9.1 or did you use pg_upgrade
previously to upgrade it _to_ 9.1?

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
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