Re: Constraint and Index with same name? (chicken and egg probelm) - Mailing list pgsql-general

From Tom Lane
Subject Re: Constraint and Index with same name? (chicken and egg probelm)
Date
Msg-id 28587.1175014744@sss.pgh.pa.us
Whole thread Raw
In response to Constraint and Index with same name? (chicken and egg probelm)  (David Brain <dbrain@bandwidth.com>)
List pgsql-general
David Brain <dbrain@bandwidth.com> writes:
Tom Lane wrote:
>> Hm, I don't see fk_cdrsummary_cdrimportsession in there anywhere?

> That is _very_ odd - I can see it in pgadmin, and also in pg_constraint,
> but it's not showing up in pg_dump or on a '\d' in psql.

Oh really?  (looks at code...)  Hah, I have a theory.  Both pg_dump and
psql's \d command assume that tables with pg_class.reltriggers = 0 must
not have any foreign keys, and so they don't bother looking into
pg_constraint for FKs.  You mentioned that this was a Slony slave DB,
and I know that Slony sometimes plays tricks with zeroing reltriggers
temporarily.  Or it might not be Slony's fault --- if you did a
data-only dump/restore with --disable-triggers and a pre-8.1 pg_dump,
it would also zero reltriggers; then if it failed before putting back
the correct reltriggers value at the end, you could wind up in this
state.

I'm not yet sure how reltriggers = 0 would result in the observed failure,
but if you fix it do things work any better?  You should first check
to see if any tables have bogus counts:

SELECT relname, reltriggers FROM pg_class WHERE
reltriggers != (SELECT count(*) FROM pg_trigger where pg_class.oid = tgrelid);

If so you can fix them with

UPDATE pg_class SET reltriggers =
  (SELECT count(*) FROM pg_trigger where pg_class.oid = tgrelid)
WHERE relname = 'whatever';

            regards, tom lane

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