On Wed, Aug 16, 2017 at 3:31 AM, Ashutosh Bapat
<ashutosh.bapat@enterprisedb.com> wrote:
> There are two ways we can do this
> 1. In expand_inherited_rtentry(), remember (childRTE and childRTIndex)
> or just childRTIndex (using this we can fetch childRTE calling
> rtfetch()) of intermediate partitioned tables. Once we are done
> expanding immediate children, call expand_inherited_rtentry()
> recursively on this list.
>
> 2. expand_inherited_tables() scans root->parse->rtable only upto the
> end of original range table list. Make it go beyond that end,
> expanding any new entries added for intermediate partitions.
>
> FWIW, the first option allows us to keep all AppendRelInfos
> corresponding to one partitioned relation together and also expands
> the whole partition hierarchy in one go. Second will require minimal
> changes to expand_inherited_rtentry(). Both approaches will spend time
> scanning same number of RTE; the first will have them in different
> lists, and second will have them in root->parse->rtable. I don't see
> one being more attractive than the other. Do you have any opinion?
I don't like option (2). I'm not sure about option (1). I think
maybe we should have two nested loops in expanded_inherited_rtentry(),
the outer one iterating over partitioned tables (or just the original
parent RTE if partitioning is not involved) and then inner one looping
over individual leaf partitions for each partitioned table. Probably
we'd end up wanting to move at least some of the logic inside the
existing loop into a subroutine.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
