Re: Ignore invalid indexes in pg_dump.

On 2013-03-28 17:35:08 -0400, Bruce Momjian wrote:
> On Thu, Mar 28, 2013 at 10:31:51PM +0100, anarazel(at)anarazel(dot)de wrote:
> >
> >
> > Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> schrieb:
> >
> > >Bruce Momjian <bruce(at)momjian(dot)us> writes:
> > >> Should I just patch pg_upgrade to remove the "indisvalid", skip
> > >> "indisvalid" indexes, and backpatch it? Users should be using the
> > >> version of pg_upgrade to match new pg_dump. Is there any case where
> > >> they don't match? Do I still need to check for "indisready"?
> > >
> > >Yeah, if you can just ignore !indisvalid indexes that should work fine.
> > >I see no need to look at indisready if you're doing that.
> >
> > You need to look at inisready in 9.2 since thats used for about to be dropped indexes. No?
>
> Well, if it is dropped, pg_dump will not dump it. At this point though,
> pg_upgrade is either running in check mode, or it is the only user. I
> think we are OK.

Its about DROP INDEX CONCURRENTLY which can leave indexes in a partial state
visible to the outside. Either just transiently while a DROP CONCURRENLTY is
going on or even permanently if the server crashed during such a drop or
similar. c.f. index.c:index_drop

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
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