Re: relhassubclass and partitioned indexes

On Fri, Oct 19, 2018 at 06:46:15PM +0900, Amit Langote wrote:
> Thanks.  Attached a patch to set relhassubclass when an index partition is
> added to a partitioned index.

Thanks, committed after adding a test with ALTER TABLE ONLY, and
checking upgrades as well as ATTACH partition for ALTER INDEX and ALTER
TABLE.  In all cases the same code paths are taken.

>      /* update pg_inherits, if needed */
>      if (OidIsValid(parentIndexRelid))
> +    {
>          StoreSingleInheritance(indexRelationId, parentIndexRelid, 1);
>
> +        /* Also, set the parent's relhassubclass. */
> +        SetRelationHasSubclass(parentIndexRelid, true);
> +    }

Calling SetRelationHasSubclass() updates pg_class for this parent
relation.  We would need CommandCounterIncrement() if the tuple gets
updated, but that's not the case as far as I checked for all code paths
where this gets called.  This would be seen immediately by the way..
--
Michael