Re: pgsql: Assert that we don't invent relfilenodes or type OIDs in binary

Uh, is there a reason this is only an Assert(), meaning it only checks
in assert builds. pg_upgrade already has a lot of checks and they are
all fatal.

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On Tue, Jun 13, 2017 at 12:04:48AM +0000, Tom Lane wrote:
> Assert that we don't invent relfilenodes or type OIDs in binary upgrade.
>
> During pg_upgrade's restore run, all relfilenode choices should be
> overridden by commands in the dump script. If we ever find ourselves
> choosing a relfilenode in the ordinary way, someone blew it. Likewise for
> pg_type OIDs. Since pg_upgrade might well succeed anyway, if there happens
> not to be a conflict during the regression test run, we need assertions
> here to keep us on the straight and narrow.
>
> We might someday be able to remove the assertion in GetNewRelFileNode,
> if pg_upgrade is rewritten to remove its assumption that old and new
> relfilenodes always match. But it's hard to see how to get rid of the
> pg_type OID constraint, since those OIDs are embedded in user tables
> in some cases.
>
> Back-patch as far as 9.5, because of the risk of back-patches breaking
> something here even if it works in HEAD. I'd prefer to go back further,
> but 9.4 fails both assertions due to get_rel_infos()'s use of a temporary
> table. We can't use the later-branch solution of a CTE for compatibility
> reasons (cf commit 5d16332e9), and it doesn't seem worth inventing some
> other way to do the query. (I did check, by dint of changing the Asserts
> to elog(WARNING), that there are no other cases of unwanted OID assignments
> during 9.4's regression test run.)
>
> Discussion: https://postgr.es/m/19785.1497215827@sss.pgh.pa.us
>
> Branch
> ------
> REL9_6_STABLE
>
> Details
> -------
> https://git.postgresql.org/pg/commitdiff/318fd99ce7e775158c87b8515780f2663d2df429
>
> Modified Files
> --------------
> src/backend/catalog/catalog.c | 16 ++++++++++++++++
> 1 file changed, 16 insertions(+)
>
>
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Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
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