Re: Replica Identity check of partition table on subscriber

On Thu, Jun 16, 2022 at 5:24 PM Amit Langote <amitlangote09(at)gmail(dot)com> wrote:
>
> On Thu, Jun 16, 2022 at 6:42 PM Amit Kapila <amit(dot)kapila16(at)gmail(dot)com> wrote:
> > On Fri, Jun 10, 2022 at 2:26 PM Amit Langote <amitlangote09(at)gmail(dot)com> wrote:
> > > @@ -1735,6 +1735,13 @@ apply_handle_insert_internal(ApplyExecutionData *edata,
> > > static void
> > > check_relation_updatable(LogicalRepRelMapEntry *rel)
> > > {
> > > + /*
> > > + * If it is a partitioned table, we don't check it, we will check its
> > > + * partition later.
> > > + */
> > > + if (rel->localrel->rd_rel->relkind == RELKIND_PARTITIONED_TABLE)
> > > + return;
> > >
> > > Why do this? I mean why if logicalrep_check_updatable() doesn't care
> > > if the relation is partitioned or not -- it does all the work
> > > regardless.
> > >
> > > I suggest we don't add this check in check_relation_updatable().
> >
> > I think based on this suggestion patch has moved this check to
> > logicalrep_rel_mark_updatable(). For a partitioned table, it won't
> > even validate whether it can mark updatable as false which seems odd
> > to me even though there might not be any bug due to that. Was your
> > suggestion actually intended to move it to
> > logicalrep_rel_mark_updatable?
>
> No, I didn't intend to suggest that we move this check to
> logicalrep_rel_mark_updatable(); didn't notice that that's what the
> latest patch did.
>
> What I said is that we shouldn't ignore the updatable flag for a
> partitioned table in check_relation_updatable(), because
> logicalrep_rel_mark_updatable() would have set the updatable flag
> correctly even for partitioned tables. IOW, we should not
> special-case partitioned tables anywhere.
>
> I guess the point of adding the check is to allow the case where a
> leaf partition's replica identity can be used to apply an update
> originally targeting its ancestor that doesn't itself have one.
>
> I wonder if it wouldn't be better to move the
> check_relation_updatable() call to
> apply_handle_{update|delete}_internal()? We know for sure that we
> only ever get there for leaf tables. If we do that, we won't need the
> relkind check.
>

I think this won't work for updates via apply_handle_tuple_routing()
unless we call it from some other place(s) as well. It will do
FindReplTupleInLocalRel() before doing update/delete for CMD_UPDATE
case and will lead to assertion failure.

--
With Regards,
Amit Kapila.