Re: Partition-wise join for join between (declaratively) partitioned tables

On 2017/09/12 18:49, Ashutosh Bapat wrote:
> On Tue, Sep 12, 2017 at 2:17 PM, Amit Langote
> <Langote_Amit_f8(at)lab(dot)ntt(dot)co(dot)jp> wrote:
>>
>> That said, I noticed that we might need to be careful about what the value
>> of the root parent's PlanRowMark's allMarkType field gets set to. We need
>> to make sure that it reflects markType of all partitions in the tree,
>> including those that are not root parent's direct children. Is that true
>> with the proposed implementation?
>
> Yes. We include child's allMarkTypes into parent's allMarkTypes. So,
> top parent's PlanRowMarks should have all descendant's allMarkTypes,
> which is not happening in the patch right now. There are two ways to
> fix that.
>
> 1. Pass top parent's PlanRowMark all the way down to the leaf
> partitions, so that current expand_single_inheritance_child() collects
> allMarkTypes of all children correctly. But this way, PlanRowMarks of
> intermediate parent does not reflect allMarkTypes of its children,
> only top root records that.
> 2. Pass immediate parent's PlanRowMark to
> expand_single_inheritance_child(), so that it records allMarkTypes of
> its children. In expand_partitioned_rtentry() have following sequence
>
> expand_single_inheritance_child(root, parentrte, parentRTindex,
> parentrel, parentrc, childrel,
> appinfos, &childrte, &childRTindex,
> &childrc);
>
> /* If this child is itself partitioned, recurse */
> if (childrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
> {
> expand_partitioned_rtentry(root, childrte, childRTindex,
> childrel, childrc, lockmode, appinfos,
> partitioned_child_rels);
>
> /* Include child's rowmark type in parent's allMarkTypes */
> parentrc->allMarkTypes |= childrc->allMarkTypes;
> }
> so that we push allMarkTypes up the hierarchy.
>
> I like the second way, since every intermediate parent records
> allMarkTypes of its descendants.

I like the second way, too.

Thanks,
Amit