Re: Bugs in CREATE/DROP INDEX CONCURRENTLY

On 2012-11-29 16:18:07 +0530, Amit Kapila wrote:
> On Thursday, November 29, 2012 12:39 AM Tom Lane wrote.
> > Andres Freund <andres(at)2ndquadrant(dot)com> writes:
> > > On 2012-11-27 23:46:58 -0500, Tom Lane wrote:
> > >> Attached is a very preliminary draft patch for this. I've not
> > >> addressed the question of whether we can clear indcheckxmin during
> > >> transactional updates of pg_index rows, but I think it covers
> > >> everything else talked about in this thread.
> >
>
> > Attached is an updated patch for HEAD that I think is about ready to go.
> > I'll start making a back-patchable version shortly.
>
> I had verified in the Patch committed that the problem is resolved.
>
> I have a doubt related to RelationGetIndexList() function.
>
> In while loop, if index is not live then it continues, so it can be possible
> that we don't find a valid index after this while loop.
> But still after the loop, it marks relation->rd_indexvalid = 1. I am not
> able to see any problem with it, but why to mark it as valid when actually
> there is no valid index.

rd_indexvalid is just saying whether rd_indexlist is valid. A zero
element list seems to be valid to me. If we don't set rd_indexvalid
pg_index will constantly be rescanned because the result isn't
considered cached anymore.

Greetings,

Andres Freund

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